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 scanner = new Scanner(System.in);
		while (true) {
			int n = scanner.nextInt(), x = scanner.nextInt();
			if (n == 0 && x == 0) break;
			int cnt = 0;
			for (int i = 1; i <= n - 1; ++i) {
				for (int j = i + 1; j <= n; ++j) {
					int k = x - (i + j);
					if (i <= j && j <= k && 1 <= k && k <= n && k != i && k != j) ++cnt;
				}
			}
			System.out.printf("%d\n", cnt);
		}
	}
}