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;

class Program
{
    static void Main(string[] args)
    {
        int n, x, i, j, k;
        int total = 0;
        int cou = 0;

        while (true)
        {
            //整数受け取り
            string[] str = Console.ReadLine().Split(' ');
            n = int.Parse(str[0]);
            x = int.Parse(str[1]);
                
            //n, xが0の場合終了
            if (n == 0 && x == 0)
            {
                break;
            }

            //判定
            for (i = 1; i <= n; i++)
            {
                for (j = i + 1; j <= n; j++)
                {
                    for (k = j + 1; k <= n; k++)
                    {
                        total = i + j + k;

                        if (total == x)
                        {
                            cou++;
                        }
                        else
                        {
                            total = 0;
                        }
                    }
                }
            }
            Console.WriteLine(cou);
            cou = 0;
        }
    }
}