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

namespace Prac
{
    class Program
    {
        static void Main(string[] args)
        {
            var ns = new List<int>();
            var xs = new List<int>();
            var results = 0;
            var temp = new int[2];
            while (true)
            {
                temp = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
                if ((temp[0] == 0) && (temp[1] == 0))
                    break;
                ns.Add(temp[0]);
                xs.Add(temp[1]);
            }
            int k = 0;
            for (var i = 0; i < ns.Count; i++)
            {
                for (var j = 1; j <= xs[i] / 3; j++)
                {
                    k = j + 1;
                    for (; k <= (xs[i] - j) / 2; k++)
                    {
                        if (((xs[i] - j - k) <= ns[i]) && ((xs[i] - j - k) > (k)))
                            results++;
                    }
                }
            }
            Console.WriteLine(results);

        }
    
    }
}