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.Arrays;
import java.util.Scanner;
public class Main {
	public static void main(String[] args)throws Exception{
		Scanner stdIn=new Scanner(System.in);
		while(true){
			int n=stdIn.nextInt();
			int x=stdIn.nextInt();
			int ans=0;
			if(n==0&&x==0)
				System.exit(0);
			for(int i=1;i<=n;i++){
				for(int j=i+1;j<=n;j++){
					for(int k=j+1;k<=n;k++){
						if(i+j+k==x)
							ans++;
					}
				}
			}
			System.out.println(ans);
		}
	}
}