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