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 ConsoleApplication3
{
    class Program
    {
        public static void Main()
        {
            while (true)
            { int c = 0;
                var a = Console.ReadLine().Split().Select(int.Parse).ToArray();
                if (a[0] == 0 && a[1] == 0) break;
                for(int b = 1; b < a[0] ; b++)
                {
                    for (int d = 2; d < b; d++)
                    {
                        if ((a[1] - b - d) > d) { c++;break; }
                    }
                }
                Console.WriteLine(c);
            }
        }
    }
}