# d = {}
#
# d[1] = []
# d[2] = []
# d[3] = []
#
# d[1].append('str')
# d[1].append('kor')
#
#
# d[2].append('bra')
# d[2].append('mama')
#
# if 'mama' in d:
#     print('mama')
#
# l = []
# l.append(30)
# l.pop(l.index(30))
#
#
# l.remove(l.index('str'))
#
#
#
# #
# # if 'str' in d[1]:
# #     print('str')
# #
# # if 'kor' in d[1]:
# #     print('kor')

l = []
print(len(l))
l.append('key')
l.remove('key')
print(len(l))