import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        long l = sc.nextInt();
        long r = sc.nextInt();
        long min = 2018;
        if (l - r > 2018) {
            System.out.println(0);
        } else {
            for (long i = l; i < r; i++) {
                for (long j = i + 1; j <= r; j++) {
                    if (i * j % 2019 < min) {
                        min = i * j % 2019;
                    }
                    if (min == 0)
                        break;
                }
                if (min == 0)
                    break;
            }
            System.out.println(min);
        }
    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz