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: Wrong Answer)

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

public class Main {
	public static void main(String[] args) {
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    
		String x = "";
		try {
			while ((x = in.readLine()).equals("0 0") != false) {
				String[] data = x.split(" ");
				int n = Integer.parseInt(data[0]);
				int sum = (Integer.parseInt(data[1]) - 3);
				
				int num = 0;
				for (int i = 0; i < n; i++) {
					for (int j = (i + 1); (i + j) < sum; j++) {
						int k = sum - (i + j);
						if ((k > j) && (k < n)) num++;
					}
				}
				
				System.out.println(num);
			}
		} catch (NumberFormatException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		System.out.println(x);
	}
}