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 PHP (judge verdict: Accepted)

<?php
    while(true){
        list($n, $x) = explode(" ", trim(fgets(STDIN)));
        if($n + $x == 0) exit;
        
        $count = 0;
        for($i = 1; $i <= $n - 2; $i++) {
            for($j = $i + 1; $j <= $n - 1; $j++) {
                for($k = $j + 1; $k <= $n; $k++) {
                    if($i + $j + $k == $x){
                        $count++;
                    }
                }
            }
        }
        
        echo $count."\n";
    }