class com:
def __init__(self):
print("A")
class b(com):
def __init__(self):
super().__init__()
print("B")
b = b()
def add ( a,b,c=0 ):
print(a*b*c)
add(1,3)
add(1,3,4)
Y2xhc3MgY29tOgogICAgZGVmIF9faW5pdF9fKHNlbGYpOgogICAgICAgIHByaW50KCJBIikKCmNsYXNzIGIoY29tKToKICAgIGRlZiBfX2luaXRfXyhzZWxmKToKICAgICAgICBzdXBlcigpLl9faW5pdF9fKCkgIAogICAgICAgIHByaW50KCJCIikKCmIgPSBiKCkKCmRlZiBhZGQgKCBhLGIsYz0wICk6CiAgICAgICAgIHByaW50KGEqYipjKQphZGQoMSwzKQphZGQoMSwzLDQp