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, cou;
    while (1) {
        cou = 0;
        scanf("%d %d", &n, &x);
        if ((n == 0) && (x == 0)) {break;}
        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) || (k == i)) {continue;}
                    if (i + j + k == x) {
                        cou++;
                    }
                }
            }
        }
        printf("%d\n", cou / 6);
    }
    return 0;
}