
# 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:

n, ma, mb = list(map(int, input().split()))

U = 400

dp = [[[float("inf")]*(U+1) for _ in range(U+1)] for i in range(n+1)]

dp[0][0][0] = 0

for i in range(n):

  a, b, c = list(map(int, input().split()))

  for j in range(U+1):

    for k in range(U+1):

      if j<a or k<b:

        dp[i+1][j][k] = dp[i][j][k]

      else:

        dp[i+1][j][k] = min(dp[i][j][k], dp[i][j-a][k-b]+c)

ans = float("inf")

for i in range(1, 1+U//max(ma, mb)):

  na, nb = i*ma, i*mb

  ans = min(ans, dp[-1][na][nb])

if ans == float("inf"):

  print((-1))

else:

  print(ans)

# optimized version of the same code:

import numpy as np



n, ma, mb = list(map(int, input().split()))

U = 400

dp = np.full((U+1, U+1), float("inf"))

dp[0, 0] = 0

for i in range(n):

  a, b, c = list(map(int, input().split()))

  np.minimum(dp[a:, b:], dp[:-a, :-b]+c, out=dp[a:, b:])

ans = float("inf")

for i in range(1, 1+U//max(ma, mb)):

  na, nb = i*ma, i*mb

  ans = min(ans, dp[na, nb])

if ans == float("inf"):

  print((-1))

else:

  print((int(ans)))
n, ma, mb = list(map(int, input().split()))
U = 400
dp = [[[float("inf")] * (U + 1) for _ in range(U + 1)] for i in range(n + 1)]
dp[0][0][0] = 0
for i in range(n):
    a, b, c = list(map(int, input().split()))
    for j in range(U + 1):
        for k in range(U + 1):
            if j < a or k < b:
                dp[i + 1][j][k] = dp[i][j][k]
            else:
                dp[i + 1][j][k] = min(dp[i][j][k], dp[i][j - a][k - b] + c)
ans = float("inf")
for i in range(1, 1 + U // max(ma, mb)):
    na, nb = i * ma, i * mb
    ans = min(ans, dp[-1][na][nb])
if ans == float("inf"):
    print((-1))
else:
    print(ans)

import numpy as np

n, ma, mb = list(map(int, input().split()))
U = 400
dp = np.full((U + 1, U + 1), float("inf"))
dp[0, 0] = 0
for i in range(n):
    a, b, c = list(map(int, input().split()))
    np.minimum(dp[a:, b:], dp[:-a, :-b] + c, out=dp[a:, b:])
ans = float("inf")
for i in range(1, 1 + U // max(ma, mb)):
    na, nb = i * ma, i * mb
    ans = min(ans, dp[na, nb])
if ans == float("inf"):
    print((-1))
else:
    print((int(ans)))

+import numpy as np + -dp = [[[float("inf")] * (U + 1) for _ in range(U + 1)] for i in range(n + 1)] -dp[0][0][0] = 0 +dp = np.full((U + 1, U + 1), float("inf")) +dp[0, 0] = 0 -    for j in range(U + 1): -        for k in range(U + 1): -            if j < a or k < b: -                dp[i + 1][j][k] = dp[i][j][k] -            else: -                dp[i + 1][j][k] = min(dp[i][j][k], dp[i][j - a][k - b] + c) +    np.minimum(dp[a:, b:], dp[:-a, :-b] + c, out=dp[a:, b:]) -    ans = min(ans, dp[-1][na][nb]) +    ans = min(ans, dp[na, nb]) -    print(ans) +    print((int(ans)))