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(fscanf(STDIN,"%d %d",$n,$x)){
    if($n===0 and $x===0)break;
    $cnt=0;
    for($i=1;$i<=$n;$i++){
        for($j=$i+1;$j<=$n;$j++){
            $c=$x-$i-$j;
            if($c>$j and $c<=$n){
                $cnt++;
            }
        }
    }
    echo $cnt,PHP_EOL;
}