s = eval(input())



ans = ""

for i in range(len(s)):

  if (i+1) % 2 != 0:

    ans += s[i]

  

print(ans)
s = eval(input())

print((s[::2]))
s = eval(input())
ans = ""
for i in range(len(s)):
    if (i + 1) % 2 != 0:
        ans += s[i]
print(ans)

s = eval(input())
print((s[::2]))

-ans = "" -for i in range(len(s)): -    if (i + 1) % 2 != 0: -        ans += s[i] -print(ans) +print((s[::2]))