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;

class Program {
    static void Main() {
        while(true) {
            string[] stdin = Console.ReadLine().Split();
            int n = int.Parse(stdin[0]);
            int x = int.Parse(stdin[1]);
            if((n | x) == 0) break;
            int ans = 0;
            for(int i = 1; i <= n - 2; i++) {
                for(int j = i + 1; j <= n - 1; j++) if(j < x - i - j && x - i - j <= n) ans++;
            }
            Console.WriteLine(ans);
        }
    }
}