import java.util.*;
class Main{
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		int L=sc.nextInt();
		int R=sc.nextInt();
		long min=0;
		if(L%2019==0||R%2019==0||L/2019<R/2019){
			System.out.println(0);
			return;
		}

		for(long i=L;i<=R;i++){
			for(long j=i+1;j<=R;j++){
				long a=(i*j)%2019;
				if((i==L&&j==L+1)||min>a){min=a;}
			}
		}
		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