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.Scanner;
import java.lang.Math;
public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int n=1,x=1;
        while(n != 0 || x != 0){
            n = sc.nextInt();
            x = sc.nextInt();
            if(n == 0 && x == 0) break;
            int cnt = 0;
            for(int i=1;i<=n-2;i++){
                for(int j=i+1;j<=n-1;j++){
                    for(int k=j+1;k<=n;k++){
                        if(i+k+j == x){
                            cnt++;
                        }
                    }
                }
            }
            System.out.printf("%d%n",cnt);
        }
        
        sc.close();
    }
}