import java.io.IOException;
import java.util.*;

public class Main {
    public static int map[][]=new int[11][11];
    public static void main(String args[]){
        Scanner sc=new Scanner(System.in);
        long L=sc.nextLong();
        long R=sc.nextLong();

        long diff=R-L;
        long lmod=L%2019;
        if(lmod+diff>=2019){
            System.out.println(0);
            return;
        }
        
        long ans=999999;
        for(long i=L;i<R;i++){
            for(long j=i+1;j<=R;j++){
                ans=Math.min(ans,i*j%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