
# 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(_) for _ in input().split(" ")]



tmp = np.argsort(A)

tmp2= tmp + np.ones(N)

tmp3 = [int(_) for _ in tmp2.tolist()]

ans = [str(_) for _ in tmp3]



print((" ".join(ans)))

# optimized version of the same code:

N = int(eval(input()))

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



tmp = sorted(list(range(1, len(A) + 1)), key=lambda x:A[x - 1])

ans = [str(_) for _ in tmp]

print((" ".join(ans)))
import numpy as np

N = int(eval(input()))
A = [int(_) for _ in input().split(" ")]
tmp = np.argsort(A)
tmp2 = tmp + np.ones(N)
tmp3 = [int(_) for _ in tmp2.tolist()]
ans = [str(_) for _ in tmp3]
print((" ".join(ans)))

N = int(eval(input()))
A = [int(_) for _ in input().split(" ")]
tmp = sorted(list(range(1, len(A) + 1)), key=lambda x: A[x - 1])
ans = [str(_) for _ in tmp]
print((" ".join(ans)))

-import numpy as np - -tmp = np.argsort(A) -tmp2 = tmp + np.ones(N) -tmp3 = [int(_) for _ in tmp2.tolist()] -ans = [str(_) for _ in tmp3] +tmp = sorted(list(range(1, len(A) + 1)), key=lambda x: A[x - 1]) +ans = [str(_) for _ in tmp]