
# 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 functools

print((len(functools.reduce(lambda x, y: x&y,[set(input().split()[1:]) for _ in [0]*int(input().split()[0])]))))

# optimized version of the same code:

print((len(set.intersection(*[set(input().split()[1:]) for _ in [0]*int(input().split()[0])]))))
import functools

print(
    (
        len(
            functools.reduce(
                lambda x, y: x & y,
                [set(input().split()[1:]) for _ in [0] * int(input().split()[0])],
            )
        )
    )
)

print(
    (
        len(
            set.intersection(
                *[set(input().split()[1:]) for _ in [0] * int(input().split()[0])]
            )
        )
    )
)

-import functools - -            functools.reduce( -                lambda x, y: x & y, -                [set(input().split()[1:]) for _ in [0] * int(input().split()[0])], +            set.intersection( +                *[set(input().split()[1:]) for _ in [0] * int(input().split()[0])]