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 C# (judge verdict: Wrong Answer)

using System;

public class Class1
{
	public static void Main()
	{
		
			string ways = Console.ReadLine();
			string[] nx= ways.Split();
			int n = int.Parse(nx[0]);//3<=n<=100
			int x = int.Parse(nx[1]);
			int count=0;
			for(int i=1;i<=n-2;i++)
			{
				for(int j=i+1;j<=n-1;j++)
				{
					for(int k=j+1;k<=n;k++)
					{
						if(i+j+k==x)
						{
							count++;
						}
					}
				}
			}
			Console.WriteLine(count);
	}
}