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.Linq;

public class Hello{
    public static void Main(){
        // Your code here!
        while(true){
            int[] r = Console.ReadLine().Split().Select(int.Parse).ToArray();
            if (r[0] == 0 && r[1] == 0){
                break;
            }
        
            int n = r[0];
            int x = r[1];
        
            int count = 0;
        
            for(int i=1;i<=n-2;i++){
                for(int j=i+1;j<=n-1;j++){
                    for(int k=j+1;k<=n;k++){
                        if(i+j+k==x){
                            count++;
                        }
                    }
                }
            }
        
            Console.WriteLine(count);
        }
    }
}