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(list($n, $x) = explode(" ", trim(fgets(STDIN)))){
    if($n == 0 && $x == 0){
        return 1;
    }
    $count = 0;
    for($i = 1; $i <= $n; $i++){
        for($j = 1; $j <= $n; $j++){
            for($k = 1; $k <= $n; $k++){
                if($i > $j && $j > $k &&  $i + $j + $k == $x){
                    $count += 1;
                }
            }
        }
    }
    echo $count.PHP_EOL;
}