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;
//using System.Collections.Generic;
using System.Linq;

namespace solution
{
  class Class1
  {
    static void Main()
    {
      int count = 0;
      while (true)
      {
        string s = Console.ReadLine();
        if (s == "0 0") break;
        var num = s.Split().Select(int.Parse).ToArray();
        int n = num[0];
        int x = num[1];

        int jj = 2;
        int kk = 3;

        for (int i = 1; i <= n - 2; i++)
        {
          for (int j = jj; j <= n - 1; j++)
          {
            for (int k = kk; k <= n; k++)
            {
              if (i + j + k == x) count++;
            }
            kk++;
          }
          jj++;
          kk = jj + 1;
        }
        Console.WriteLine(count);
        count = 0;
      }
    }
  }
}