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 JAVA (judge verdict: Accepted)

import java.util.Scanner;

public class Main {
    public int countWays(int n, int x) {
        int count = 0;
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j < i; j++) {
                for (int k = 1; k < j; k++) {
                    if (i + j + k == x) {
//                        System.out.println(i + "+" + j + "+" + k);
                        count++;
                    }
                }
            }
        }
        return count;
    }

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        Main app = new Main();

        while (true) {
            int inN, inX;
            int count;

            inN = Integer.parseInt(scan.next());
            inX = Integer.parseInt(scan.next());
            if (inN == 0 && inX == 0) break;

            count = app.countWays(inN, inX);
            System.out.println(count);
        }
    }
}