
# 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(eval(input()))

A = [int(x) for x in input().split()]



tmp = [x for x in zip(A, list(range(1, N+1)))]

tmp = np.array(sorted(tmp))

print((*tmp[:,1]))

# optimized version of the same code:

N = int(eval(input()))

A = [int(x) for x in input().split()]

B = [0 for _ in range(N)]

for i in range(N):

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

print((*B))
import numpy as np

N = int(eval(input()))
A = [int(x) for x in input().split()]
tmp = [x for x in zip(A, list(range(1, N + 1)))]
tmp = np.array(sorted(tmp))
print((*tmp[:, 1]))

N = int(eval(input()))
A = [int(x) for x in input().split()]
B = [0 for _ in range(N)]
for i in range(N):
    B[A[i] - 1] = i + 1
print((*B))

-import numpy as np - -tmp = [x for x in zip(A, list(range(1, N + 1)))] -tmp = np.array(sorted(tmp)) -print((*tmp[:, 1])) +B = [0 for _ in range(N)] +for i in range(N): +    B[A[i] - 1] = i + 1 +print((*B))