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 (($line = trim(fgets(STDIN))) !== '') {
    sscanf($line, '%d %d', $n, $x);

    if ($n === 0 && $x === 0) {
        break;
    }

    $result = array();
    for ($i = 1; $i <= $n; $i++) {
        for ($j = $i + 1; $j <= $n; $j++) {
            if ($i + $j >= $x) {
                break;
            }

            $k = $x - $i - $j;

            if ($k <= $n && $k > 0 && $k !== $j && $k !== $i) {
                $arr = array($i, $j, $k);
                sort($arr);
                $str = implode(',', $arr);
                if (!in_array($str, $result)) {
                    $result[] = $str;
                }
            }
        }
    }

    echo count($result), PHP_EOL;
}