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.*;

public class Main{
    public static void main(String[]args)throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        while(true){
            int count = 0;
            String[] str = br.readLine().split(" ");
            int n = Integer.parseInt(str[0]);
            int x = Integer.parseInt(str[1]);

            if(n == 0 && x == 0)break;
            for(int i=1; i<=n; i++){
                for(int k=1; k<=n; k++){
                    for(int w=1; w<=n; w++){
                        if(i!=k && k!=w && i!=w && (i+k+w) == x)count++;
                    }
                }
            }
            System.out.println(count / 6);
        }
    }
}