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 AOZ
{
	class MainClass
	{
		static void Main(string[] args)
		{
			while (true)
			{
				var input = Console.ReadLine();
				if (input == "0 0")
					break;
				var arr_input = input.Split(' ').Select(int.Parse).ToArray();
				var n = arr_input[0]; var x = arr_input[1];
				var ans_cnt = 0;
				for (int i = 1; i <= n; i++)
					for (int j = i + 1; j <= n; j++)
						for (int k = j + 1; k <= n; k++)
						{
							var sum = i + j + k;
							if (sum == x) { ans_cnt++; /*Console.WriteLine(i.ToString()+" "+j.ToString()+" "+k.ToString());*/k = n; }
							else if (sum > x) { k = n; }
						}
				Console.WriteLine(ans_cnt);
			}
		}
	}
}