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

        long min = 2019;
        for (long i = l; i <= r - 1; i++) {
            for (long j = i+1; j <= r; j++) {
                long mod = (i * j) % 2019;
                if (min > mod) {
                    min = mod;
                }
            }
        }
        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