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: Time Limit Exceeded)

#include <stdio.h>


int main() {
    int n, x, i, j, k;
    int a[100][2];
    int count;
    
    while(1){
        for(i = 0; i < 100; i++){
            scanf("%d %d", &n, &x);
            if(n==0 && x==0)
               break;
            else{
                a[i][0] = n;
                a[i][1] = x;
            }
        }
        for(i = 0; i <= a[i][1]; i++){
            count = 0;
            for(j = i + 1; j <= a[i][0]; j++){
                for(k = j + 1; k <= a[i][0]; k++){
                    if (i + j + k == a[i][1])
                        count++;
                }
            }
            printf("%d\n", count);
        }
    }
}