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 i, j, k;
	int count=0;

	while(1){
		scanf("%d %d", &n, &x);	/* n?????\?????????3??\???100??\?????¨?????? */
			if((n==0)&&(x==0)) {
			break;	/* n x??±???0????????\????????? */
	}

	for (i=1; i<=n; i++) {
		for (j=1; j<=n; j++) {
			for (k=1; k<=n; k++) {
				if (i+j+k==x && i!=j && j!=k && k!=i) {
					count++;	/* ???????????????????????£?????¨??????????????????????????? */
				}
			}
		}
	}

	printf("%d\n", count/6);	/* ??????????????????????????????????????°????????? */
		count=0;
	}

	return 0;
}