
# 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:

K,S = list(map(int,input().split(" ")))

ans = 0

for i in range(K+1):

	for j in range(K+1):

		if (S - i - j) <= K and (S-i-j) >= 0:

			ans += 1



print(ans)


# optimized version of the same code:

K, S = list(map(int,input().split(" ")))

ans = 0

for X in range(K+1):

    for Y in range(K+1):

        if 0 <= (S - X - Y) <= K:

            ans += 1



print(ans)
K, S = list(map(int, input().split(" ")))
ans = 0
for i in range(K + 1):
    for j in range(K + 1):
        if (S - i - j) <= K and (S - i - j) >= 0:
            ans += 1
print(ans)

K, S = list(map(int, input().split(" ")))
ans = 0
for X in range(K + 1):
    for Y in range(K + 1):
        if 0 <= (S - X - Y) <= K:
            ans += 1
print(ans)

-for i in range(K + 1): -    for j in range(K + 1): -        if (S - i - j) <= K and (S - i - j) >= 0: +for X in range(K + 1): +    for Y in range(K + 1): +        if 0 <= (S - X - Y) <= K: