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