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 PHP (7.4.4) (judge verdict: Wrong Answer)

<?php
// Your code here!
    fscanf(STDIN,"%d%d",$L,$R);
    
    //LRの間に2019の倍数を含む場合は0
    // echo ($R-$L)."\n";
    if($R-$L>=2017){
        echo "0";
        exit;
    }
    
    for($i=$L;$i<=$R;$i++){
        // echo ($i%2019)."\n";
        if($i%2019==0){
            echo "0";
            exit;
        }
    }
    $I = intval(floor($L/2019));
    
    for($i=$L;$i<=$R;$i++){
        $array[$i] = abs($I*2019-$i);
    }
    $A = array_shift($array);
    $B = array_shift($array);
    echo ($A*$B)%2019;
    // var_dump($array);
?>