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;
public class Hello{
    public Hello(){}
    public static void Main(){
       new Hello().Calc();
    }
    void Calc(){
        var inputs = InputValues;
        foreach(var i in inputs){
            Console.WriteLine(i);
        }
    }
    List<int> InputValues{
        get{
            var inputs = new List<int>();
            while(true){
                var a = Array.ConvertAll(Console.ReadLine().Split(' '),int.Parse);
                var N = a[0];
                var X = a[1];
                var count = 0;
                if(N == 0 && X == 0){
                    break;
                }
                for(var x = 1;x <= N - 2;x++){
                    for(var y = x + 1;y <= N - 1;y++){
                        for(var z = y + 1;z <= N;z++){
                            if(x + y + z == X){
                               count++;  
                            }
                        }
                    }
                }
                inputs.Add(count);
            }
            return inputs;
        }
    }
    
}