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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) throws IOException {
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		int n, x, ways;
		while (true) {
			ways = 0;
			String[] num = in.readLine().split(" ");
			n = Integer.parseInt(num[0]);
			x = Integer.parseInt(num[1]);
			if (n == 0 && x == 0) {
				break;
			}
			for (int i = 1; i <= n; i += 1) {
				for (int j = 1; j <= n; j += 1) {
					for (int k = 1; k <= n; k += 1) {
						if (i == j || j == k || i == k) {
							continue;
						} else if (i + j + k == x) {
							ways++;
						}
					}
				}
			}
			System.out.println(ways / 6);
		}
	}
}