
# 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 = int(eval(input()))

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

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

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

A.sort()

C.sort()



ans = 0

from bisect import bisect, bisect_left

for b in B:

    i = bisect_left(A, b)

    j = bisect(C, b)

    ans += i * (N-j)

print(ans)

# optimized version of the same code:

N = int(eval(input()))

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

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

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

A.sort()

C.sort()



from bisect import bisect_left, bisect

ans = 0

for b in B:

    i = bisect_left(A,b)

    j = bisect(C,b)

    ans += i * (N-j)

print(ans)
N = int(eval(input()))
A = list(map(int, input().split()))
B = list(map(int, input().split()))
C = list(map(int, input().split()))
A.sort()
C.sort()
ans = 0
from bisect import bisect, bisect_left

for b in B:
    i = bisect_left(A, b)
    j = bisect(C, b)
    ans += i * (N - j)
print(ans)

N = int(eval(input()))
A = list(map(int, input().split()))
B = list(map(int, input().split()))
C = list(map(int, input().split()))
A.sort()
C.sort()
from bisect import bisect_left, bisect

ans = 0
for b in B:
    i = bisect_left(A, b)
    j = bisect(C, b)
    ans += i * (N - j)
print(ans)

+from bisect import bisect_left, bisect + -from bisect import bisect, bisect_left -