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;
using System.Threading.Tasks;


namespace ConsoleApp6
{
	class Program
	{
		static void Main(string[] args)
		{
			while (true)
			{
				var nx = Console.ReadLine().Split(' ');
				int n = int.Parse(nx[0]);
				int x = int.Parse(nx[1]);

				if (n == 0 && x == 0)
					break;

				int i, j, k;
				int count = 0;
				//i + j + k = x

				for (i = n; 0 < i; i--)
				{
					for (j = n; 0 < j; j--)
					{
						for (k = n; 0 < k; k--)
						{
							if (k < j && j < i && i + j + k == x)
							{
								count++;
							}
						}
					}
				}
				Console.WriteLine(count);
			}
		}
	}
}