
# 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:

from collections import defaultdict



from scipy.misc import comb



N, M = list(map(int, input().split()))

A = [int(x) for x in input().split()]



B = [0] * N

B[0] = A[0]

for i in range(1, N):

    B[i] = B[i - 1] + A[i]

B = [0] + B



c = defaultdict(int)

for i in range(N + 1):

    c[B[i] % M] += 1



ans = 0

for k, v in list(c.items()):

    if v >= 2:

        ans += comb(v, 2, exact=True)

print(ans)

# optimized version of the same code:

from collections import defaultdict



N, M = list(map(int, input().split()))

A = [int(x) for x in input().split()]



B = [0] * N

B[0] = A[0]

for i in range(1, N):

    B[i] = B[i - 1] + A[i]

B = [0] + B



c = defaultdict(int)

for i in range(N + 1):

    c[B[i] % M] += 1



ans = 0

for k, v in list(c.items()):

    if v >= 2:

        ans += v * (v - 1) // 2

print(ans)
from collections import defaultdict
from scipy.misc import comb

N, M = list(map(int, input().split()))
A = [int(x) for x in input().split()]
B = [0] * N
B[0] = A[0]
for i in range(1, N):
    B[i] = B[i - 1] + A[i]
B = [0] + B
c = defaultdict(int)
for i in range(N + 1):
    c[B[i] % M] += 1
ans = 0
for k, v in list(c.items()):
    if v >= 2:
        ans += comb(v, 2, exact=True)
print(ans)

from collections import defaultdict

N, M = list(map(int, input().split()))
A = [int(x) for x in input().split()]
B = [0] * N
B[0] = A[0]
for i in range(1, N):
    B[i] = B[i - 1] + A[i]
B = [0] + B
c = defaultdict(int)
for i in range(N + 1):
    c[B[i] % M] += 1
ans = 0
for k, v in list(c.items()):
    if v >= 2:
        ans += v * (v - 1) // 2
print(ans)

-from scipy.misc import comb -        ans += comb(v, 2, exact=True) +        ans += v * (v - 1) // 2