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;

namespace Project
{
	class MainClass
	{
		public static void Main(string[] args)
		{
			while (true)
			{
				string s = Console.ReadLine();
				string[] sar = s.Split(' ');
				int n = int.Parse(sar[0]);
				int x = int.Parse(sar[1]);
				if (n == 0 && x == 0) { break;}
				int count = 0;
				for (int i = 0; i < n; i++)
				{
					for (int j = i+1; j < n; j++)
					{
						for (int k = j+1; k < n; k++)
						{
							if (i + j + k + 3 == x) { count++; }
						}
					}
				}
				Console.WriteLine(count);
			}
		}
	}
}