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: Accepted)

<?php
  
fscanf(STDIN,"%d%d",$l,$r);
$min = 2019;
for($i=$l;$i<$r;$i++){
  for($j=$l+1;$j<=$r;$j++){
    if(($i*$j)%2019==0){
      echo "0";
      exit;
    }
    $min = min(($i*$j)%2019,$min);
  }
}

echo $min;