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.Linq;

class A
{
    static void Main(string[] args)
    {
        int ans;
        while (true)
        {
            ans = 0;
            int[] s = Console.ReadLine().Split().Select(int.Parse).ToArray();
            if (s[0] == s[1] && s[0] == 0) { break; }
            for (int i = 1; i <= s[0]; i++)
            {
                for (int k = 1; k <= s[0]; k++)
                {
                    for (int m = 1; m <= s[0]; m++)
                    {
                        if (i + k + m == s[1] && i != m && m != k && i != k)
                        {
                            ans++;
                        }
                    }
                }

            }
            Console.WriteLine(ans/6);
        }
    }
}