
# 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



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



N=temp[0]

X=temp[1]



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



ind=1

while np.sum(L[:ind])<=X and ind<=N:

  ind+=1

  

print(ind)

# optimized version of the same code:

N, X=list(map(int, input().split()))

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

L=[0]+L

 

l=int(0)

counter=int(0)

while l+L[counter]<=X and counter<=N:

  l+=L[counter]

  counter+=int(1)

  if counter==N+1:

    break

  

print(counter)
import numpy as np

temp = list(map(int, input().split()))
N = temp[0]
X = temp[1]
L = list(map(int, input().split()))
ind = 1
while np.sum(L[:ind]) <= X and ind <= N:
    ind += 1
print(ind)

N, X = list(map(int, input().split()))
L = list(map(int, input().split()))
L = [0] + L
l = int(0)
counter = int(0)
while l + L[counter] <= X and counter <= N:
    l += L[counter]
    counter += int(1)
    if counter == N + 1:
        break
print(counter)

-import numpy as np - -temp = list(map(int, input().split())) -N = temp[0] -X = temp[1] +N, X = list(map(int, input().split())) -ind = 1 -while np.sum(L[:ind]) <= X and ind <= N: -    ind += 1 -print(ind) +L = [0] + L +l = int(0) +counter = int(0) +while l + L[counter] <= X and counter <= N: +    l += L[counter] +    counter += int(1) +    if counter == N + 1: +        break +print(counter)