def f(x):
if x >= 5:
if x <= 9:
return True
else:
for i in range(5,10):
if f(x - i):
return True
return False
else:
return False
print(4)
ZGVmIGYoeCk6CglpZiB4ID49IDU6CgkJaWYgeCA8PSA5OgoJCQlyZXR1cm4gVHJ1ZQoJCWVsc2U6CgkJCWZvciBpIGluIHJhbmdlKDUsMTApOgoJCQkJaWYgZih4IC0gaSk6CgkJCQkJcmV0dXJuIFRydWUKCQkJcmV0dXJuIEZhbHNlCgllbHNlOgoJCXJldHVybiBGYWxzZQpwcmludCg0KQ==