
# 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:

import numpy as np



N = int(input())

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



# for i in range(N):

#   print(As.index(i+1) + 1, end = " ")



for item in np.argsort(As):

  print(item+1, end=" ")


# optimized version of the same code:

N = int(eval(input()))

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



ans = [0] * N



for i, A in enumerate(As):

  ans[A-1] = i+1

  

print((*ans))
import numpy as np

N = int(input())
As = list(map(int, input().split()))
# for i in range(N):
#   print(As.index(i+1) + 1, end = " ")
for item in np.argsort(As):
    print(item + 1, end=" ")

N = int(eval(input()))
As = list(map(int, input().split()))
ans = [0] * N
for i, A in enumerate(As):
    ans[A - 1] = i + 1
print((*ans))

-import numpy as np - -N = int(input()) +N = int(eval(input())) -# for i in range(N): -#   print(As.index(i+1) + 1, end = " ") -for item in np.argsort(As): -    print(item + 1, end=" ") +ans = [0] * N +for i, A in enumerate(As): +    ans[A - 1] = i + 1 +print((*ans))