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);

		int n = sc.nextInt();
		int x = sc.nextInt();

		while(!(n == 0&&x==0)){
		int count = 0;
		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++;
						break;
					}

				}
			}
		}
		System.out.println(count);

		n = sc.nextInt();
		x = sc.nextInt();
		}
	}
}