import java.util.Scanner;

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

		long l = Integer.parseInt(sc.next());
		long r = Integer.parseInt(sc.next());

		long min = Integer.MAX_VALUE;

		for (long i = l; i < r; i++) {
			for (long j = i + 1; j <= r; j++) {
				long mod = (i % 2019 * j % 2019) % 2019;
				if (mod == 0) {
					System.out.println(0);
					System.exit(0);
				} else if (mod < min) {
					min = mod;
				}
			}
		}
		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