s = eval(input())

ans = ""

for i in range(len(s)//2+1):

    if 2*i < len(s):

      ans += s[2*i]

    else:

        break

print(ans)
import math

s = eval(input())

ans = ""

for i in range(math.ceil(len(s)/2)):

    ans += s[2*i]

print(ans)
s = eval(input())
ans = ""
for i in range(len(s) // 2 + 1):
    if 2 * i < len(s):
        ans += s[2 * i]
    else:
        break
print(ans)

import math

s = eval(input())
ans = ""
for i in range(math.ceil(len(s) / 2)):
    ans += s[2 * i]
print(ans)

+import math + -for i in range(len(s) // 2 + 1): -    if 2 * i < len(s): -        ans += s[2 * i] -    else: -        break +for i in range(math.ceil(len(s) / 2)): +    ans += s[2 * i]