
# slower version:

s = input()
for i in range(len(s)):
  if i%2 == 0:
    print(s[i], end = '')


# optimized version of the same code:

s = input()
ans = ''
for i in range(len(s)):
  if i % 2 == 0:
    ans += s[i]
print(ans)



# slower version:

# C - Go to School

def main():

    import numpy as np

    n = int(input())

    a = list(map(int, input().split()))

    a = np.array(a)

    a = np.argsort(a)

    for i in a:

        print(i+1,end=" ")



if __name__ ==  "__main__":

    main()


# optimized version of the same code:

# C - Go to School

def main():

    n = int(eval(input()))

    a = list(map(int, input().split()))

    ans = [0] * n



    for i, o in enumerate(a):

        ans[o-1] = i + 1 

    

    print((*ans))



if __name__ ==  "__main__":

    main()
# C - Go to School
def main():
    import numpy as np

    n = int(input())
    a = list(map(int, input().split()))
    a = np.array(a)
    a = np.argsort(a)
    for i in a:
        print(i + 1, end=" ")


if __name__ == "__main__":
    main()

# C - Go to School
def main():
    n = int(eval(input()))
    a = list(map(int, input().split()))
    ans = [0] * n
    for i, o in enumerate(a):
        ans[o - 1] = i + 1
    print((*ans))


if __name__ == "__main__":
    main()

-    import numpy as np - -    n = int(input()) +    n = int(eval(input())) -    a = np.array(a) -    a = np.argsort(a) -    for i in a: -        print(i + 1, end=" ") +    ans = [0] * n +    for i, o in enumerate(a): +        ans[o - 1] = i + 1 +    print((*ans))