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
echo solve();
function solve() {
    fscanf(STDIN, "%d %d", $l, $r);
    if (intval(floor($r / 2019)) - intval(floor($l / 2019)) > 0) return 0;
    $mods = [2018]; $temp = 0;
    for ($i=$l; $i < $r; $i++) {
        for ($j=$i + 1; $j <= $r; $j++) {
            $temp = (($i % 2019) * ($j % 2019)) % 2019;
            if ($temp == 1) return 1;
            $mods[] = $temp;
        }
    }
    return min($mods);
}
?>