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.*;

class Main {
    public static void main (String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] input;
        int n, x, i, j, k, num;

        while (true) {
            input = br.readLine().split(" ");
            n = Integer.parseInt(input[0]);
            x = Integer.parseInt(input[1]);
            if (n == 0 && x == 0) break;
            num = 0;
            for (i = 1; i <= n; i++) {
                for (j = i + 1; j <= n; j++) {
                    for (k = j + 1; k <= n; k++) {
                        if (x - i - j - k == 0) num++;
                    }
                }
            }
            System.out.println(num);
        }
    }
}