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.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace How_many_ways
{
    class Program
    {
        static void Main(string[] args)
        {
            int range = 0;
            int sum = 0;
            List<int> results = new List<int>();

            while(true)
            {
                string input = Console.ReadLine();
                if(input.Equals("0 0"))
                {
                    break;
                }
                string[] temp = input.Split(' ');
                
                range = int.Parse(temp[0]);
                sum = int.Parse(temp[1]);

                int count = 0;

                for (int i = 1; i <= range; i++)
                {
                    for (int j = i + 1; j <= range; j++)
                    {
                        for (int k = j + 1; k <= range; k++)
                        {
                            if (i + j + k == sum)
                            {
                                ++count;
                            }
                        }
                    }
                }

                results.Add(count);
                
            }

            foreach (int item in results)
            {
                Console.WriteLine(item);
            }

            


        }
    }
}