
# 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





def lcm(x, y):

    return (x * y) // fractions.gcd(x, y)





N = int(eval(input()))

print((lcm(N, 2)))

# optimized version of the same code:

N = int(eval(input()))

if N % 2 == 0:

    print(N)

else:

    print((2 * N))
import fractions


def lcm(x, y):
    return (x * y) // fractions.gcd(x, y)


N = int(eval(input()))
print((lcm(N, 2)))

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

-import fractions - - -def lcm(x, y): -    return (x * y) // fractions.gcd(x, y) - - -print((lcm(N, 2))) +if N % 2 == 0: +    print(N) +else: +    print((2 * N))