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: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Aizu
{
	class Program
	{
		static void Main(string[] args)
		{
			var datas = new List<List<int>>();

			while(true)
			{
				datas.Add(Console.ReadLine().Split(' ').Select(value => int.Parse(value)).ToList());
				if(datas[datas.Count - 1][0] == 0 && datas[datas.Count - 1][1] == 0)
				{
					break;
				}
			}

			datas.RemoveAt(datas.Count - 1);


			foreach(var data in datas)
			{
				var count = 0;
				for (var i = 1; i <= data[0] - 2; i++)
				{
					for(var j = i + 1; j <= data[0] - 1; j++)
					{
						for(var k = j + 1; k <= data[0]; k++)
						{
							if(i + j + k == data[1])
							{
								count++;
							}
						}
					}
				}

				Console.WriteLine(count);
			}
		}
	}
}