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