
# 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

from copy import deepcopy



N = int(eval(input()))

A = []

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

a = deepcopy(A[0])

a.sort()

A.append(a)

A_t = np.array(A).T.tolist()

A_t.sort()



out = []

for i in range(N):

    out.append(str(A_t[i][1]))

print((" ".join(out)))


# optimized version of the same code:

N = int(eval(input()))

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



rev = [""] * N

for i in range(N):

    rev[A[i]-1] = str(i+1)

print((" ".join(rev)))

import numpy as np
from copy import deepcopy

N = int(eval(input()))
A = []
A.append(list(map(int, input().split())))
a = deepcopy(A[0])
a.sort()
A.append(a)
A_t = np.array(A).T.tolist()
A_t.sort()
out = []
for i in range(N):
    out.append(str(A_t[i][1]))
print((" ".join(out)))

N = int(eval(input()))
A = list(map(int, input().split()))
rev = [""] * N
for i in range(N):
    rev[A[i] - 1] = str(i + 1)
print((" ".join(rev)))

-import numpy as np -from copy import deepcopy - -A = [] -A.append(list(map(int, input().split()))) -a = deepcopy(A[0]) -a.sort() -A.append(a) -A_t = np.array(A).T.tolist() -A_t.sort() -out = [] +A = list(map(int, input().split())) +rev = [""] * N -    out.append(str(A_t[i][1])) -print((" ".join(out))) +    rev[A[i] - 1] = str(i + 1) +print((" ".join(rev)))