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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		while(true){
			String[] tmp = br.readLine().split(" ");
			int n = Integer.parseInt(tmp[0]);
			int x = Integer.parseInt(tmp[1]);
			if(n == 0 && x == 0){
				break;
			}
			int start = x / 3 + 1;
			int count = 0;
			for(int i = start;i <= n;i++){
				for(int j = ((start << 1) - (i + 1));j < i;j++){
					for(int k = 1;k < j;k++){
						if((i + j + k) == x){
							count++;
							break;
						}
					}
				}
			}
			System.out.println(count);
		}
	}

}