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)

def main():
    while True:
        n, x = map(int, input().split())
        if n == x == 0:
            break
        number = 0
        for i in range(n):
            j = i + 1
            if x - j > n*2 - 1:
                continue
            elif x - j <= j:
                break
            else:
                for k in range(x - j):
                    m = k + 1
                    if k < j:
                        continue
                    elif (x - j - m) >= m and x - j - m <= n:
                        number += 1
                        break
                    else:
                        continue
        print(number)
    return


if __name__ == '__main__':
    main()