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) {
		@SuppressWarnings("resource")
		Scanner scan = new Scanner(System.in);
		while (true) {
			int n = scan.nextInt();
			int x = scan.nextInt();
			if (n == 0 && x == 0)
				break;
			System.out.println(run(n, x));
		}
		System.exit(0);
	}

	private static int run(int n, int x) {
		int result = 0;
		for (int a = 1; a <= n; a++)
			for (int b = a + 1; b <= n; b++)
				for (int c = b + 1; c <= n; c++)
					if (a + b + c == x)
						++result;
		return (result);

	}
}