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