import java.util.Scanner;

public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		long L = sc.nextLong(), R = sc.nextLong();
		if(R - L > 2019) System.out.println(0);
		else {
			long ans = Long.MAX_VALUE;
			for(long i = L; i <= R; i++) {
				for(long j = i + 1; j <= R; j++) {
					ans = Math.min(ans, (i * j) % (long)2019);
				}
			}
			System.out.println(ans);
		}
	}
}

/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