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

ans = 0

a = np.array(a)

while a.size > 0:

    a = a[a%2 == 0]

    ans += len(a)

    a = a//2

print(ans)

# optimized version of the same code:

n = int(eval(input()))

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

ans = 0

for i in range(n):

    while a[i]%2 == 0:

        a[i] //=2

        ans+=1

print(ans)
import numpy as np

N = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
a = np.array(a)
while a.size > 0:
    a = a[a % 2 == 0]
    ans += len(a)
    a = a // 2
print(ans)

n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
for i in range(n):
    while a[i] % 2 == 0:
        a[i] //= 2
        ans += 1
print(ans)

-import numpy as np - -N = int(eval(input())) +n = int(eval(input())) -a = np.array(a) -while a.size > 0: -    a = a[a % 2 == 0] -    ans += len(a) -    a = a // 2 +for i in range(n): +    while a[i] % 2 == 0: +        a[i] //= 2 +        ans += 1