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, i, ii, iii, a;
	int all = 0;

	for (a = 0; a < 1; a--) {
		scanf("%d%d", &n, &x);

		if (n == 0 && x == 0) break;
		
		for (i = 1; i <= n; i++) {
			for (ii = 1; ii <= n; ii++) {
				for (iii = 1; iii <= n; iii++) {
					if (i != ii && i != iii && ii != iii && i < ii && ii < iii && i < iii) {
						if (i + ii + iii == x) {
							all++;
						}
					}
				}
			}
		}
		printf("%d\n", all);
		all = 0;
	}
	return 0;
}