# s = input()
# if len(s) % 2 == 0:
#     while len(s) >= 2:
#         print(s)
#         s = s[1:-1]
# else:
#     while len(s) >= 2:
#         print(s)
#         s = s[1:-1]

s = input()
while len(s) >= 1:
    print(s)
    s = s[1:-1]
