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: Wrong Answer)

using System;
using System.Linq;

class A
{
    static void Main(string[] args)
    {
        while (true)
        {
            string hsda = Console.ReadLine();
            if (hsda == null) { break; }
            int ans = 0;
            //int a = int.Parse(hsda);
            int[] s = Console.ReadLine().Split().Select(int.Parse).ToArray();

            for (int i = 1; i < s[0]; i++)
            { 
                for (int k = 1; k < s[0]; k++)
                {
                    if (i == k) { }
                    else
                    {
                        for (int m = 1; m < s[0]; m++)
                        {
                            if (i == m||m==k) { }
                            else
                            {
                                for (int i1 = 1; i1 < s[0]; i1++)
                                {
                                    if (i == i1||k==i1||m==i1) { }
                                    else
                                    {
                                        if (i + k + m + i1 == s[1])
                                        {
                                            if (i != m && i != i1 && k != m && k != i1 && m != i1)
                                            {
                                                ans++;
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }
            Console.WriteLine(ans);
        }
    }
}