
# 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 fractions

n=int(eval(input()))

print(((2*n)//fractions.gcd(2,n)))

# optimized version of the same code:

N=int(eval(input()));print((N if N%2==0 else N*2))
import fractions

n = int(eval(input()))
print(((2 * n) // fractions.gcd(2, n)))

N = int(eval(input()))
print((N if N % 2 == 0 else N * 2))

-import fractions - -n = int(eval(input())) -print(((2 * n) // fractions.gcd(2, n))) +N = int(eval(input())) +print((N if N % 2 == 0 else N * 2))