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();

        long min = Long.MAX_VALUE;
        if (r - l > 2019) {
            min = 0;
        } else {
            flag:
            for (long i = l; i < r; i++) {
                for (long j = l + 1; j <= r; j++) {
                    min = Math.min(min, (i * j) % 2019);
                    if (min == 0) break flag;
                }
            }
        }


        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