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 JAVA (judge verdict: Accepted)

import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author silviase
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Howmanyways solver = new Howmanyways();
        solver.solve(1, in, out);
        out.close();
    }

    static class Howmanyways {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            while (true) {
                int n = in.nextInt();
                int x = in.nextInt();
                if (n == 0 && x == 0) return;
                // 1~n
                int res = 0;
                for (int i = 1; i < n; i++) {
                    for (int j = i + 1; j < n; j++) {
                        if (x - i - j > j && x - i - j <= n) res++;
                    }
                }
                out.println(res);
            }
        }

    }
}