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;
    do
    {
        int count = 0;
        scanf("%d %d", &n, &x);
        if (n != 0 || x != 0)
        {

            for (int i = 1; i <= n; i++)
            {
                for (int j = 1; j <= n; j++)
                {
                    for (int k = 1; k <= n; k++)
                    {
                        if (i < j && j < k && i + j + k == x)
                            count++;
                    }
                }
            }
            printf("%d\n", count);
        }
    } while (n != 0 || x != 0);
    return 0;
}