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 scan = new Scanner(System.in);
		for(int a = 1;a>0;a++){
			int n =scan.nextInt();
			int x = scan.nextInt();
			int H = 0;
			if(n == 0 && x == 0){
				break;
			}
			int k[] = new int[n];
			for(int b = 0;b<n;b++){
				k[b] = b+1;
			}
			for(int c = 0;c<n-2;c++){
				for(int d = 1;d+c<n;d++){
					for(int e = 1;e+d+c<n;e++){
						if(k[c] + k[d+c] + k[e+d+c] == x){
							H++;
						}
					}
				}
			}
			System.out.println(H);
		}
	}

}