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 Perl (v5.18.2) (judge verdict: Wrong Answer)

($l,$r)=glob<>;
$l%=2019;
$r%=2019;
$r=$r<$l?$r+2019:$r;
$min=2019;

for$i($l..$r-1){
    for$j($i+1..$r){
        $min=$min<($t=$i*$j%2019)?$min:$t;
    }
}
print $min