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.*;
import java.util.*;

class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        while(true){
        	String in=br.readLine();
			if(in.equals("0 0")) break;
            String[] a=in.split(" ");
            int n=Integer.parseInt(a[0]);
            int x=Integer.parseInt(a[1]);
            List<String> l=new ArrayList<String>(); 
        	for(int i=1;i<=n;i++){
            	for(int j=2;j<=n;j++){
                	for(int k=3;k<=n;k++){
                		if(i!=j&&j!=k&&k!=i&&i+j+k==x){
                			int[] q={i, j, k};
                			Arrays.sort(q);
                			String s=Arrays.toString(q);
                			if(l.indexOf(s)==-1) l.add(s);
                		}
                	}
            	}
        	}
        	System.out.println(l.size());
        }
	}
}