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



count = 0

while np.all(a%2==0):

    count+=1

    a=a/2

print(count)


# optimized version of the same code:

N=int(eval(input()))

a = [int(i) for i in input().split()]



count=0

while 1:

    if sum([i%2 for i in a]) == 0:

        a = [i/2 for i in a]

        count=count+1

    else:

        print(count)

        break

import numpy as np

n = int(eval(input()))
a = np.array(list(map(int, input().split())))
count = 0
while np.all(a % 2 == 0):
    count += 1
    a = a / 2
print(count)

N = int(eval(input()))
a = [int(i) for i in input().split()]
count = 0
while 1:
    if sum([i % 2 for i in a]) == 0:
        a = [i / 2 for i in a]
        count = count + 1
    else:
        print(count)
        break

-import numpy as np - -n = int(eval(input())) -a = np.array(list(map(int, input().split()))) +N = int(eval(input())) +a = [int(i) for i in input().split()] -while np.all(a % 2 == 0): -    count += 1 -    a = a / 2 -print(count) +while 1: +    if sum([i % 2 for i in a]) == 0: +        a = [i / 2 for i in a] +        count = count + 1 +    else: +        print(count) +        break