Traceback (most recent call last):
File "./prog.py", line 10, in <module>
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
File "/usr/lib/python3.7/_collections_abc.py", line 801, in pop
del self[key]
File "./prog.py", line 5, in __delitem__
RecursionError: maximum recursion depth exceeded