
# 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 math

n = int(eval(input()))

print((math.factorial(n)%(10**9+7)))

# optimized version of the same code:

n = int(eval(input()))

ans = 1

mod = 10**9+7

for i in range(1, n+1):

    ans *= i

    ans %= mod



ans %= mod

print(ans)

import math

n = int(eval(input()))
print((math.factorial(n) % (10**9 + 7)))

n = int(eval(input()))
ans = 1
mod = 10**9 + 7
for i in range(1, n + 1):
    ans *= i
    ans %= mod
ans %= mod
print(ans)

-import math - -print((math.factorial(n) % (10**9 + 7))) +ans = 1 +mod = 10**9 + 7 +for i in range(1, n + 1): +    ans *= i +    ans %= mod +ans %= mod +print(ans)