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