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.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int cnt = 0;
        while (true) {
            int n = sc.nextInt();
            int x = sc.nextInt();
            if (n == 0 && x == 0) {
                break;
            }
            for (int i = 1; i <= n - 2; i++) {
                for (int j = 2; j <= n - 1; j++) {
                    for (int k = 3; k <= n; k++) {
                        if (i >= j) {
                            j = i + 1;
                        }
                        if (i >= k) {
                            k = i + 1;
                        }
                        if (j >= k) {
                            k = j + 1;
                        }
                        if ((i + j + k) == x) {
                            cnt++;
                        }
                    }
                }
            }
             System.out.println(cnt);
             cnt = 0;
        }
       
    }

}