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;
import java.io.*;

public class Main
{
	public static void main(String args[])
	{
		Scanner sc = new Scanner(System.in);
		int n, x, ans;
		while(true)
		{
			n = sc.nextInt();
			x = sc.nextInt();
			ans = 0;
			if(n == 0 && x == 0)
			{
				break;
			}
			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 && j != k && i != k && i + j + k == x)
						{
							++ans;
						}
					}
				}
			}
			System.out.println(ans);
		}
		sc.close();
	}
}