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.Collections.Generic;
using System.Collections;


namespace ConsoleApplication21
{
    class Program
    {
        static void Main(string[] args)
        {
            for (int Roop = 0; Roop < Roop + 1; )
            {
                String[] input = Console.ReadLine().Split(' ');
                int n = int.Parse(input[0]);
                int x = int.Parse(input[1]);
                int[] An = new int[n];
                int S = 0;
                int Ans = 0;
                if (n == 0 && x == 0)
                    break;
                else
                {
                    for (int i = 0; i < n; i++)
                    {
                        An[i] = S + 1;
                        S = S + 1;
                    }
                    for (int z = 0; z < n; z++)
                    {
                        int a = An[z];
                        for (int y = 0; y < n; y++)
                        {
                            int b = An[y];
                            for (int v = 0; v < n; v++)
                            {
                                int c = An[v];
                                if ( (a != b || b != c || c != a) && (x == a + b + c) )
                                        Ans = Ans + 1;
                                
                            }
                        }
                    }
                    Console.WriteLine((Ans/6)-1);
                }
            }
        }
    }
}