
# 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())



A=np.array([list(map(int, input().split()))])





B=np.argsort(A[0,:])

for b in B:

  print(b+1, end=' ')


# optimized version of the same code:

N=int(input())



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

B=[-1]*N

for i in range(N):

  B[A[i]-1]=i+1

  

for b in B:

  print(b, end=" ")

import numpy as np

N = int(input())
A = np.array([list(map(int, input().split()))])
B = np.argsort(A[0, :])
for b in B:
    print(b + 1, end=" ")

N = int(input())
A = list(map(int, input().split()))
B = [-1] * N
for i in range(N):
    B[A[i] - 1] = i + 1
for b in B:
    print(b, end=" ")

-import numpy as np - -A = np.array([list(map(int, input().split()))]) -B = np.argsort(A[0, :]) +A = list(map(int, input().split())) +B = [-1] * N +for i in range(N): +    B[A[i] - 1] = i + 1 -    print(b + 1, end=" ") +    print(b, end=" ")