import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int l = sc.nextInt();
        int r = sc.nextInt();
        int result = 2018;
        loop: for (long i = l; i < r; i++) {
            for (long j = i + 1; j <= r; j++) {
                result = Math.min(result, (int)((i * j) % 2019));
                if ((i * j) % 2019 == 0) {
                    break loop;
                }
            }
        }
        System.out.println(result);
        sc.close();
    }
}
/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