Problem:
How many ways?

Write a program which identifies the number of combinations of three integers which satisfy the following conditions:

You should select three distinct integers from 1 to n.

A total sum of the three integers is x.

For example, there are two combinations for n = 5 and x = 9.

1 + 3 + 5 = 9

2 + 3 + 4 = 9

Input

The input consists of multiple datasets. For each dataset, two integers n and x are given in a line.

The input ends with two zeros for n and x respectively. Your program should not process for these terminal symbols.

Constraints

3 ≤ n ≤ 100

0 ≤ x ≤ 300

Output

For each dataset, print the number of combinations in a line.

Sample Input

5 9
0 0

Sample Output

2

Note

      解説

Solution in Python3 (judge verdict: Wrong Answer)

# AOJ ITP1_7_B

def numinput():
    a = input().split()
    for i in range(len(a)):
        a[i] = int(a[i])
    return a

def main():
    while True:
        a = numinput()
        n = a[0]; x = a[1]
        if n == 0 and x == 0: break
        # 1からnまでの異なる3つの数の和がxになる数の組の個数。
        count = 0
        for i in range(1, (x // 3) + 1):
            for j in range(i + 1, (x // 3) + 1):
                if j < x - i - j <= n: count += 1
            if i > (n // 3): break
        print(count)

if __name__ == "__main__":
    main()