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[100], x[100], l, i, j, k, c[100];
 
    for (l = 0; l < 100; l++) {
        scanf("%d %d", &n[l], &x[l]);
        if (n[l] == 0 && x[l] == 0) 
            break;
    }
    
    for (l = 0; l < 100 ; l++) {
        if (n[l] == 0 && x[l] == 0) 
            break;
        c[l] = 0;
        for (i = 1; i <= n[l]; i++) {
            for (j = i + 1; j <= n[l]; j++) {
                for (k = j + 1; j <= n[l]; k++) {
                    if (i + j + k == x[l])
                        c[l]++;
                }
            }
        }
    }
 
    for (l = 0; l < 100 ; l++) {
        if (n[l] == 0 && x[l] == 0) 
            break;
        printf("%d\n", c[l]);
    }
 
    return 0;
}