# Problem https://atcoder.jp/contests/abc072/tasks/abc072_b

# Python 2nd Try





class Problem:

    def __init__(self, problemstring):

        self.problemstring = problemstring

        self.length = len(self.problemstring)



    def solve(self):

        result = ''

        resultlist = []

        for j in range(0, self.length):

            if j % 2 == 0:

                resultlist.append(self.problemstring[j])

        result = ''.join(resultlist)

        return result





if __name__ == "__main__":

#    S = "atcoder"

#    print("{} => {}".format(S, Problem(S).solve()))

#    S = "aaaa"

#    print("{} => {}".format(S, Problem(S).solve()))

#    S = "z"

#    print("{} => {}".format(S, Problem(S).solve()))

    S = eval(input())

    print((Problem(S).solve()))
# Problem https://atcoder.jp/contests/abc072/tasks/abc072_b

# Python 3rd Try

import copy





class Problem:

    def __init__(self, inputstring):

        self.inputstring = inputstring



    def __str__(self):

        return self.inputstring



    def solver(self):

        result = ''

        string = copy.copy(self.inputstring)

        result = string[0:len(string):2]

        return result





if __name__ == "__main__":

    s = eval(input())

    x = Problem(s)

    print((x.solver()))

# Problem https://atcoder.jp/contests/abc072/tasks/abc072_b
# Python 2nd Try
class Problem:
    def __init__(self, problemstring):
        self.problemstring = problemstring
        self.length = len(self.problemstring)

    def solve(self):
        result = ""
        resultlist = []
        for j in range(0, self.length):
            if j % 2 == 0:
                resultlist.append(self.problemstring[j])
        result = "".join(resultlist)
        return result


if __name__ == "__main__":
    #    S = "atcoder"
    #    print("{} => {}".format(S, Problem(S).solve()))
    #    S = "aaaa"
    #    print("{} => {}".format(S, Problem(S).solve()))
    #    S = "z"
    #    print("{} => {}".format(S, Problem(S).solve()))
    S = eval(input())
    print((Problem(S).solve()))

# Problem https://atcoder.jp/contests/abc072/tasks/abc072_b
# Python 3rd Try
import copy


class Problem:
    def __init__(self, inputstring):
        self.inputstring = inputstring

    def __str__(self):
        return self.inputstring

    def solver(self):
        result = ""
        string = copy.copy(self.inputstring)
        result = string[0 : len(string) : 2]
        return result


if __name__ == "__main__":
    s = eval(input())
    x = Problem(s)
    print((x.solver()))

-# Python 2nd Try +# Python 3rd Try +import copy + + -    def __init__(self, problemstring): -        self.problemstring = problemstring -        self.length = len(self.problemstring) +    def __init__(self, inputstring): +        self.inputstring = inputstring -    def solve(self): +    def __str__(self): +        return self.inputstring + +    def solver(self): -        resultlist = [] -        for j in range(0, self.length): -            if j % 2 == 0: -                resultlist.append(self.problemstring[j]) -        result = "".join(resultlist) +        string = copy.copy(self.inputstring) +        result = string[0 : len(string) : 2] -    #    S = "atcoder" -    #    print("{} => {}".format(S, Problem(S).solve())) -    #    S = "aaaa" -    #    print("{} => {}".format(S, Problem(S).solve())) -    #    S = "z" -    #    print("{} => {}".format(S, Problem(S).solve())) -    S = eval(input()) -    print((Problem(S).solve())) +    s = eval(input()) +    x = Problem(s) +    print((x.solver()))