
# 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 numpy as np

N = int(eval(input()))

abc = []

for i in range(N):

    abc.append(list(map(int, input().split())))

    

dp = np.zeros(shape=(N, 3), dtype=int)

dp[0, :] = abc[0]

for i in range(N-1):

    dp[i+1, 0] = max(dp[i+1, 0], dp[i, 1] + abc[i+1][0], dp[i, 2] + abc[i+1][0])

    dp[i+1, 1] = max(dp[i+1, 1], dp[i, 0] + abc[i+1][1], dp[i, 2] + abc[i+1][1])

    dp[i+1, 2] = max(dp[i+1, 2], dp[i, 0] + abc[i+1][2], dp[i, 1] + abc[i+1][2])

print((max(dp[N-1, :])))

# optimized version of the same code:

N = int(eval(input()))

abc = []

for i in range(N):

    data = list(map(int, input().split()))

    abc.append(data)



dp = [[0 for i in range(3)] for j in range(N)]

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

dp[0][1] = abc[0][1]

dp[0][2] = abc[0][2]



for i in range(N-1):

    for j in range(3):

        if j == 0:

            dp[i+1][1] = max(dp[i][0] + abc[i+1][1], dp[i+1][1])

            dp[i+1][2] = max(dp[i][0] + abc[i+1][2], dp[i+1][2])

        if j == 1:

            dp[i+1][0] = max(dp[i][1] + abc[i+1][0], dp[i+1][0])

            dp[i+1][2] = max(dp[i][1] + abc[i+1][2], dp[i+1][2])

        if j == 2:

            dp[i+1][1] = max(dp[i][2] + abc[i+1][1], dp[i+1][1])

            dp[i+1][0] = max(dp[i][2] + abc[i+1][0], dp[i+1][0])



print((max(dp[N-1])))
import numpy as np

N = int(eval(input()))
abc = []
for i in range(N):
    abc.append(list(map(int, input().split())))
dp = np.zeros(shape=(N, 3), dtype=int)
dp[0, :] = abc[0]
for i in range(N - 1):
    dp[i + 1, 0] = max(dp[i + 1, 0], dp[i, 1] + abc[i + 1][0], dp[i, 2] + abc[i + 1][0])
    dp[i + 1, 1] = max(dp[i + 1, 1], dp[i, 0] + abc[i + 1][1], dp[i, 2] + abc[i + 1][1])
    dp[i + 1, 2] = max(dp[i + 1, 2], dp[i, 0] + abc[i + 1][2], dp[i, 1] + abc[i + 1][2])
print((max(dp[N - 1, :])))

N = int(eval(input()))
abc = []
for i in range(N):
    data = list(map(int, input().split()))
    abc.append(data)
dp = [[0 for i in range(3)] for j in range(N)]
dp[0][0] = abc[0][0]
dp[0][1] = abc[0][1]
dp[0][2] = abc[0][2]
for i in range(N - 1):
    for j in range(3):
        if j == 0:
            dp[i + 1][1] = max(dp[i][0] + abc[i + 1][1], dp[i + 1][1])
            dp[i + 1][2] = max(dp[i][0] + abc[i + 1][2], dp[i + 1][2])
        if j == 1:
            dp[i + 1][0] = max(dp[i][1] + abc[i + 1][0], dp[i + 1][0])
            dp[i + 1][2] = max(dp[i][1] + abc[i + 1][2], dp[i + 1][2])
        if j == 2:
            dp[i + 1][1] = max(dp[i][2] + abc[i + 1][1], dp[i + 1][1])
            dp[i + 1][0] = max(dp[i][2] + abc[i + 1][0], dp[i + 1][0])
print((max(dp[N - 1])))

-import numpy as np - -    abc.append(list(map(int, input().split()))) -dp = np.zeros(shape=(N, 3), dtype=int) -dp[0, :] = abc[0] +    data = list(map(int, input().split())) +    abc.append(data) +dp = [[0 for i in range(3)] for j in range(N)] +dp[0][0] = abc[0][0] +dp[0][1] = abc[0][1] +dp[0][2] = abc[0][2] -    dp[i + 1, 0] = max(dp[i + 1, 0], dp[i, 1] + abc[i + 1][0], dp[i, 2] + abc[i + 1][0]) -    dp[i + 1, 1] = max(dp[i + 1, 1], dp[i, 0] + abc[i + 1][1], dp[i, 2] + abc[i + 1][1]) -    dp[i + 1, 2] = max(dp[i + 1, 2], dp[i, 0] + abc[i + 1][2], dp[i, 1] + abc[i + 1][2]) -print((max(dp[N - 1, :]))) +    for j in range(3): +        if j == 0: +            dp[i + 1][1] = max(dp[i][0] + abc[i + 1][1], dp[i + 1][1]) +            dp[i + 1][2] = max(dp[i][0] + abc[i + 1][2], dp[i + 1][2]) +        if j == 1: +            dp[i + 1][0] = max(dp[i][1] + abc[i + 1][0], dp[i + 1][0]) +            dp[i + 1][2] = max(dp[i][1] + abc[i + 1][2], dp[i + 1][2]) +        if j == 2: +            dp[i + 1][1] = max(dp[i][2] + abc[i + 1][1], dp[i + 1][1]) +            dp[i + 1][0] = max(dp[i][2] + abc[i + 1][0], dp[i + 1][0]) +print((max(dp[N - 1])))