
# 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

import math



def bigger_devisor(n):

  s = np.sqrt(n)

  i = math.ceil(s)

  while(n % i != 0):

    i += 1

  return i



n = int(eval(input()))

if bigger_devisor(n) > 9:

  print('No')

else:

  print('Yes')

# optimized version of the same code:

n = int(eval(input()))

ans = 0

for i in range(1, 10):

  if n % i == 0:

    if n / i < 10:

      ans = 1

if ans == 0:

  print('No')

else:

  print('Yes')
import numpy as np
import math


def bigger_devisor(n):
    s = np.sqrt(n)
    i = math.ceil(s)
    while n % i != 0:
        i += 1
    return i


n = int(eval(input()))
if bigger_devisor(n) > 9:
    print("No")
else:
    print("Yes")

n = int(eval(input()))
ans = 0
for i in range(1, 10):
    if n % i == 0:
        if n / i < 10:
            ans = 1
if ans == 0:
    print("No")
else:
    print("Yes")

-import numpy as np -import math - - -def bigger_devisor(n): -    s = np.sqrt(n) -    i = math.ceil(s) -    while n % i != 0: -        i += 1 -    return i - - -if bigger_devisor(n) > 9: +ans = 0 +for i in range(1, 10): +    if n % i == 0: +        if n / i < 10: +            ans = 1 +if ans == 0: