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.*;
public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while(true) {
            int a = sc.nextInt();
            int b = sc.nextInt();

            if(a==0 && b == 0){
                break;
            }else{
                int ans = 0;
                for(int i = 1 ; i <= a-2 ; i++){
                    for(int j = i+1 ; j <= a-1 ; j++){
                        for(int k = j+1 ; k <= a ; k++){
                            if(i+j+k == b){
                                ans++;
                            }else{
                            }
                        }
                    }
                }
                System.out.println(ans);
            }
        }
    }
}