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: Time Limit Exceeded)

import java.io.*;
public class Main {
	public static void main(String[] args) throws IOException{
		BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
		while(true){
			String line = reader.readLine();
			String[] str = line.split(" ", -1);
			int n = Integer.parseInt(str[0]);
			int x = Integer.parseInt(str[1]);
			if(n == 0 && x == 0){
				break;
			}
			int count = 0;
			int a = 1;
			int b = 2;
			int c = 3;
			while(true){
				if(c > n){
					b++;
					if(b == 5){
						a++;
						b = a + 1;
						c = a + 2;
					}else{
						c = b + 1;
					}
				}
				if(a + b + c == x){
					count++;
				}
				if(a == n - 1){
					break;
				}
				c++;
			}
			System.out.println(count);
		 }
	}
}