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.*;

public class Main{
	public static void main(String[] args){

		Scanner scan = new Scanner(System.in);
		List<Integer> listN = new ArrayList<Integer>();
		List<Integer> listX = new ArrayList<Integer>();
		for(;;){
			int n = scan.nextInt();
			int x = scan.nextInt();
			if((n == 0) && (x == 0)){
				break;
			}
			listN.add(n);
			listX.add(x);
		}

		for(int i = 0; i < listN.size(); i++){
			int n = listN.get(i);
			int x = listX.get(i);
			int cnt = 0;
			for(int a = 1; a <= n; a++){
				for(int b = a + 1; b <= n; b++){
					for(int c = b + 1; c <= n; c++){
						int sum = a + b + c;
						if(sum == x){
							cnt++;
						}
					}
				}
			}
			System.out.println(cnt);
		}
	}
}