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,j,k,a;

	a=0;
	n=1;
	x=1;

	while(n!=0 || x!=0){
		scanf("%d %d",&n,&x);
		if(n==0 && x==0){
			break;
		}
		for(i=1;i<=n-2;i++){
			for(j=2;j<=n-1;j++){
				for(k=3;k<=n;k++){
					if((i+j+k)==x && i!=j && j!=k && k!=i && i<j && j<k){
						a++;
					}
				}
			}
		}
		printf("%d\n",a);
		a=0;
	}

	return 0;
}