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 + x == 0) break;
            int ans = 0;
            for(int a = 1; a <= n - 2; a++)
                for(int b = a + 1; b <= n - 1; b++)
                    for(int c = b + 1; c <= n; c++) {
                        if(a + b + c == x) ans++;
                    }
            System.out.println(ans);
        }
    }
}