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));
	StringBuilder keepfile = new StringBuilder();

 String[] str;

	while(true) {
	//??\???????????????????????????
      str = br.readLine().split(" "); 
	  int n = Integer.parseInt(str[0]);
	  int x = Integer.parseInt(str[1]);;
	  if(n == 0 & x == 0) break;

	//?¨??????????????????????????????? 
      else if(n != 0 & x != 0 | n >= 3 & n <= 100 | x >= 0 & x <= 300) {


     int N = 0 ; //N ???????¨????x??¨????????????????????????????????°??§???
         for(int i = 1; i <= n ; i++) {
	        for(int j = (i+1) ; j <= n ; j++) {
	           int k = 0 ;
	           k = x-i-j ; //x = i+j+k ???????????????k=x-i-j ??¨?????????
               if(j < k & k <= n) N++; 
	       }

	     }
	keepfile.append(N).append("\n");
	}

	}

	//??????????????????????????????
     System.out.print(keepfile);

	br.close();
	}
}