
# 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:

a, b, c = list(map(int, input().split()))



if a < b + c:

    print((b+c-a))

else:

    print((0))

# optimized version of the same code:

a,b,c = list(map(int, input().split()))



print((max(0, c-(a-b))))
a, b, c = list(map(int, input().split()))
if a < b + c:
    print((b + c - a))
else:
    print((0))

a, b, c = list(map(int, input().split()))
print((max(0, c - (a - b))))

-if a < b + c: -    print((b + c - a)) -else: -    print((0)) +print((max(0, c - (a - b))))