
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();
		
		int l2 = (int) (l % 2019);
		int r2 = (int) (r % 2019);

		if(r - l > 2019) {
			System.out.println(0);
		}
		else if(l2 <= r2) {
			int min = l2 * r2 % 2019;
			for (int i = l2; i <= r2; i++) {
				for (int j = i+1; j <= r2; j++) {
					int mod = i * j % 2019;
					if(min > mod) {
						min = mod;
					}
				}
			}
			System.out.println(min);
		}else {
			System.out.println(0);
		}
	}
}

/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