
# 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:

eval(input())



import numpy as np

A = np.array(list(map(int, input().split(" "))))

a = 0



while np.sum(A%2) == 0:

  A = A/2

  a = a + 1



print(a)

# optimized version of the same code:

eval(input())



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

B = 0



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

  A = [a/2 for a in A]

  B += 1

  

print(B)

    
eval(input())
import numpy as np

A = np.array(list(map(int, input().split(" "))))
a = 0
while np.sum(A % 2) == 0:
    A = A / 2
    a = a + 1
print(a)

eval(input())
A = list(map(int, input().split(" ")))
B = 0
while all(a % 2 == 0 for a in A):
    A = [a / 2 for a in A]
    B += 1
print(B)

-import numpy as np - -A = np.array(list(map(int, input().split(" ")))) -a = 0 -while np.sum(A % 2) == 0: -    A = A / 2 -    a = a + 1 -print(a) +A = list(map(int, input().split(" "))) +B = 0 +while all(a % 2 == 0 for a in A): +    A = [a / 2 for a in A] +    B += 1 +print(B)