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);

        while(true) {
            int n = sc.nextInt();
            int x = sc.nextInt();

            if (n == 0 && x == 0)
                break;

            int count = 0;

            int n1 = 1, n2 = 2, n3 = 3;

            for (n1 = 1; n1<= n - 2; n1++) {
                for (n2 = n1 + 1; n2<= n - 1; n2++) {
                    for(n3 = n2 + 1; n3 <= n; n3++){
                        if(n1 + n2 + n3 == x)
                            count++;
                    }
                }
            }
            System.out.println(count);
        }
    }
}