import java.util.Scanner;

public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        long l = sc.nextLong();
        long r = sc.nextLong();

        if (l >= r) {
            System.out.print(0);
        } else if (r - l > 2019) {
            System.out.print(0);
        } else {
            l = l % 2019;
            r = r % 2019;

            long min = 2018;
            for (long i = l; i < r; i++) {
                for (long j = i + 1; j <= r; j++) {
                    if ((i * j) % 2019 < min) {
                        min = (i * j) % 2019;
                    }
                }
            }
            System.out.print(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