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;

class Program
{
    static void Main()
    {
        int sum = 0;
        while (true)
        {
            string[] s = Console.ReadLine().Split(' ');
            int n = int.Parse(s[0]);
            int x = int.Parse(s[1]);
            if (n == 0 && x == 0)
                break;
            else
            {
                for(int i =1;i<=n;i++)
                {
                    for (int j = i+1; j<=n;j++ )
                    {
                        for (int k = j+1; k<=n; k++)
                        {
                            if (i + j + k == x)
                                sum += 1;
                        }
                    }
                }
            }
            Console.WriteLine(sum);
        }
    }
}