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;

namespace _001_FindingMissingCards
{
    /*
     */

    class Program
    {
        static void Main()
        {
            Boolean cont = true;

            while (cont)
            {
                string line = Console.ReadLine();
                string[] line_split = line.Split(' ');
                int n = Convert.ToInt32(line_split[0]);
                int x = Convert.ToInt32(line_split[1]);
                if (n == 0 && x == 0)
                {
                    cont = false;
                }
                else
                {
                    int count = 0;
                    for (int i = 1; i <= n - 2; i++)
                    {
                        for (int j = i + 1; j <= n - 1; j++)
                        {
                            for (int k = j + 1; k <= n; k++)
                            {
                                if (i + j + k == x)
                                {
                                    count++;
                                }
                            }
                        }
                    }
                    Console.WriteLine(count);
                }
            }

            
        }
    }
}