
# 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

N = int(input())

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

inds = numpy.argsort(A)

inds+=1

for ind in inds:

  print(ind, end=' ')


# optimized version of the same code:

N = int(eval(input()))

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

ans = [0]*N

for i,a in enumerate(A):

  ans[a-1] = i+1

print((*ans))
import numpy

N = int(input())
A = list(map(int, input().split()))
inds = numpy.argsort(A)
inds += 1
for ind in inds:
    print(ind, end=" ")

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

-import numpy - -N = int(input()) +N = int(eval(input())) -inds = numpy.argsort(A) -inds += 1 -for ind in inds: -    print(ind, end=" ") +ans = [0] * N +for i, a in enumerate(A): +    ans[a - 1] = i + 1 +print((*ans))