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 C (judge verdict: Accepted)

#include <stdio.h> 
int main(void)
{
	int n, x;
	int b, i, j, k, a;

	while (1) {
		scanf("%d %d", &n, &x);
		b = 0;
		if (n == 0 && x == 0) {
			break;
		}
		for (k = 1; k <= n; k++) {
			for (j = 1; j <= n; j++) {
				for (i = 1; i <= n; i++) {
					if (i == j || j == k || i == k) {
					}
					else {
						a = i + j + k;
						if (a == x) {
							b += 1;
						}
					}
				}//i
			}//j
		}//k
		printf("%d\n", b / 6);
	}
	return 0;
}