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: Wrong Answer)

import java.io.*;
import java.util.*;

public class Main { 
	public static void main(String args[]) throws IOException{
		Scanner scr = new Scanner(System.in);
		while (true){
		    try{
				String[] str = scr.nextLine().split(" ", 0);
				int n = Integer.parseInt(str[0]);
				int x = Integer.parseInt(str[0]);
				if (n==0 && x==0) break; //??\?????????
				System.out.println( SearchTrio(n, x) );
			}catch(Exception e){
				System.err.println("Exception");
				break;
			}
        }
		scr.close();
	}
	
	
	private static int SearchTrio(int n, int x){
		int r=0;
	    for(int i=1; i<=(n/3); i++){
	    	r += SearchPair(i, n, x-i);
		}
	    return r;
	}
	
	private static int SearchPair(int min, int max, int x){
		int r=0;
		for(int i=min; i<(min + max)/2; i++){
			if( x - i < max) r++;
		}
		return r;
	}
}