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 static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		while (true) {
			int count = 0;
			int n = sc.nextInt();
			int x = sc.nextInt();
			if (n == 0 && x == 0)
				break;

			for (int i = 1; i <= n - 2; i++) {
				for (int j = i + 1; j <= n - 1; j++) {
					for (int k = j + 1; k <= n; k++) {
						if (i + j + k == x) {
							count++;
						}
					}
				}
			}
			System.out.println(count);
		}
		sc.close();
	}

}