
# 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()))



A = np.array(A)

counter = 0

while True:

    if all( i%2==0 for i in A):

        counter  += 1

        A = A/2

    else:

        print(counter)

        break

# optimized version of the same code:

N = int(eval(input()))

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



c = 0

while True:

    if all(a% 2 ==0 for a in A):

        c += 1

        A = list([x//2 for x in A])

    else:

        break

print(c)
import numpy as np

N = int(eval(input()))
A = list(map(int, input().split()))
A = np.array(A)
counter = 0
while True:
    if all(i % 2 == 0 for i in A):
        counter += 1
        A = A / 2
    else:
        print(counter)
        break

N = int(eval(input()))
A = list(map(int, input().split()))
c = 0
while True:
    if all(a % 2 == 0 for a in A):
        c += 1
        A = list([x // 2 for x in A])
    else:
        break
print(c)

-import numpy as np - -A = np.array(A) -counter = 0 +c = 0 -    if all(i % 2 == 0 for i in A): -        counter += 1 -        A = A / 2 +    if all(a % 2 == 0 for a in A): +        c += 1 +        A = list([x // 2 for x in A]) -        print(counter) +print(c)