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 == 0 && $x == 0) break;
    for($i = 0; $i < $n; $i++) $arr[$i] = ($i + 1);
    $count = 0;
    for($i = 0; $i < $n; $i++){
        for($j = 0; $j < $n; $j++){
            for($k = 0; $k < $n; $k++){
                if($i == $j || $j == $k || $k == $i) continue;
                $s = $arr[$i]+$arr[$j]+$arr[$k];
                if($s == $x){
                    // echo ($i+1)." ".($j+1)." ".($k+1)."\n";
                    $count++;
                }
            }
        }
    }
    echo ($count / 6)."\n";
}