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($num=trim(fgets(STDIN))){
    $num = array_map('intval',explode(" ",$num));
    if($num==[0,0])break;
    $n = $num[0];
    $x = $num[1];
    $count=0;
    for($i=1;$i<=$n;$i++){
        for($j=$i+1;$j<=$n;$j++){
            for($k=$j+1;$k<=$n;$k++){
                if(($i+$j+$k==$x) && ((($i!=$j) &&($j!=$k)) &&($i!=$k))){
                    $count++;
                }
            }
        }
    }
    echo $count."\n";
}
?>