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 N = R;

		if (R > L + 2019) {
			N = L + 2019;
		}
		int ans = Integer.MAX_VALUE;
		for (long i = L; i <= N; i++) {
			for (long j = i + 1; j <= N; j++) {
				ans = (int) Math.min(ans, i * j % 2019);
			}
		}
		System.out.println(ans);
		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