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;
using System.Text;
class Program
{
    static void Main()
    {
        int[] beta = new int[2];
        while (true)
        {

            string[] alpha = Console.ReadLine().Split(' ');
            for (int i = 0; i < 2; i++) beta[i] = int.Parse(alpha[i]);
            if (beta[0] == 0 && beta[1] == 0) break;                        /*//if 0 0, break*/
            int unt = beta[0];
            int sumd = beta[1];
            int[] num = new int[150];
            for (int i = 0; i < unt; i++) num[i] = i;
            int count = 0;
            /*//unt までの数字を抽出*/
            for (int i = 1; ; i++)
            {
                if (i == unt+1) break;                                      /*//unt まで確認したら計算終了*/
                {
                    for (int j = 1; ; j++)
                    {
                        if (j == unt+1) break;
                        for (int k = 1; ; k++)
                        {
                            if (k == unt+1) break;
                            if (i == j || i == k || j == k||i ==0||j==0||k==0) break;
                            { if (i + j + k == sumd) count++; }
                        }
                    }
                }
            }
            Console.WriteLine(count/2);
        }
    }
}