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;

enum occupant
{
build, floor, room, number
}

class Program
 {


     
     static void Main(string[] args)
     {
         String nyuryoku;
         string[] data = new string[3];
         string[] data1;
         int num, sum, temp;
         var result = new List<int>();

         while (true)
         {
             nyuryoku = Console.ReadLine();
             data = nyuryoku.Split(' ');
             num = int.Parse(data[0]);
             sum = int.Parse(data[1]);

             if (num == 0 & sum == 0)
                 break;
             temp = 0;
             for (int i = 1; i <= num; i++)
             {
                 for (int j = i + 1; j <= num; j++)
                     for (int k = j + 1; k <= num; k++)
                         if ((i + j + k) == sum)
                             temp++;
             }
             result.Add(temp);
         }
         for (int l=0; l < result.Count; l++)
             Console.WriteLine("{0}",result[l]);
    




      }
 }