#!/usr/bin/env python3

# -*- coding: utf-8 -*-

import math





def main():

    S = list(input())

    for s in range(0, len(S), 2):

        print(S[s], end='')





if __name__ == "__main__":

    main()

#!/usr/bin/env python3

# -*- coding: utf-8 -*-

import math





def main():

    S = eval(input())

    print((S[::2]))





if __name__ == "__main__":

    main()

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import math


def main():
    S = list(input())
    for s in range(0, len(S), 2):
        print(S[s], end="")


if __name__ == "__main__":
    main()

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import math


def main():
    S = eval(input())
    print((S[::2]))


if __name__ == "__main__":
    main()

-    S = list(input()) -    for s in range(0, len(S), 2): -        print(S[s], end="") +    S = eval(input()) +    print((S[::2]))