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;

namespace AizuOnLine
{
    class Program
    {
        static void Main(string[] args)
        {
            while (true)
            {
                string[] data = Console.ReadLine().Split(' ');
                int n = int.Parse(data[0]);
                int x = int.Parse(data[1]);

                if(n == 0 && x == 0)
                {
                    break;
                }

                int count = 0;
                for (int a = 1; a <= n; a++)
                {
                    if (x < 2 * a + 1)
                    {
                        break;
                    }

                    for (int b = a + 1; b < n; b++)
                    {
                        int c = x - a - b;
                        if (x < a + 2 * b + 1)
                        {
                            break;
                        }
                        else if (n < c)
                        {
                            continue;
                        }

                        count++;
                    }

                }

                Console.WriteLine(count);
            }
        }
    }
}