Problem:
Score : 300 points

Problem Statement

You are given two non-negative integers L and R.
We will choose two integers i and j such that L \leq i < j \leq R.
Find the minimum possible value of (i \times j) \mbox{ mod } 2019.

Constraints

All values in input are integers.

0 \leq L < R \leq 2 \times 10^9

Input

Input is given from Standard Input in the following format:

L R

Output

Print the minimum possible value of (i \times j) \mbox{ mod } 2019 when i and j are chosen under the given condition.

Sample Input 1

2020 2040

Sample Output 1

2

When (i, j) = (2020, 2021), (i \times j) \mbox{ mod } 2019 = 2.

Sample Input 2

4 5

Sample Output 2

20

We have only one choice: (i, j) = (4, 5).

Solution in PHP7 (7.0.15) (judge verdict: Wrong Answer)

<?php
# 入力
list($l, $r) = array_map('intval', explode(' ', trim(fgets(STDIN))));
$l %= 2019;
$r %= 2019;
$min = 2019;
for ($i = $l; $i <= $r - 1; $i++) {
    for ($j = $i + 1; $j <= $r; $j++) {
        $n = ($i * $j) % 2019;
        if ($min > $n) {
            $min = $n;
        }
    }
}
echo $min.PHP_EOL;
?>