
# 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()))



SUM = 0

for i in A:

    count = 0

    while i%2 == 0:

        i//=2

        count += 1

    SUM+=count

print(SUM)

# optimized version of the same code:

N = int(eval(input()))

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

SUM = 0

for i in A:

    while i%2 == 0:

        i//=2

        SUM += 1

print(SUM)
N = int(eval(input()))
A = list(map(int, input().split()))
SUM = 0
for i in A:
    count = 0
    while i % 2 == 0:
        i //= 2
        count += 1
    SUM += count
print(SUM)

N = int(eval(input()))
A = list(map(int, input().split()))
SUM = 0
for i in A:
    while i % 2 == 0:
        i //= 2
        SUM += 1
print(SUM)

-    count = 0 -        count += 1 -    SUM += count +        SUM += 1