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 scan = new Scanner(System.in);

		int way = 0;

		while(true) {
			int n = scan.nextInt();
			int x = scan.nextInt();

			if(n == 0 && x == 0) {
				break;
			}

			way = 0;
			for(int i = 1; i <= n; i++) {
				for(int j = i + 1; j <= n; j++) {
					for(int k = j + 1; k <= n; k++) {
						if(i + j + k == x) {
							way++;
						}
					}
				}
			}
			System.out.println(way);
		}

		scan.close();
	}
}