
# 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()))

print((2**int(np.log2(N))))

# optimized version of the same code:

import math

N=int(eval(input()))

print((2**int(math.log2(N))))
import numpy as np

N = int(eval(input()))
print((2 ** int(np.log2(N))))

import math

N = int(eval(input()))
print((2 ** int(math.log2(N))))

-import numpy as np +import math -print((2 ** int(np.log2(N)))) +print((2 ** int(math.log2(N))))