import java.util.Scanner;

class Main{
    public static void main(String[] args){
        Scanner scn=new Scanner(System.in);
        long L =scn.nextLong();
        long R =scn.nextLong(); 
        R=Math.min(R,L+4038);
        long answer = 2018;
        for(long i=L;i<=R;i++){
            for(long j=i+1;j<=R;j++){
                long x = i*j%2019;
                answer=Math.min(answer,x);
            }
        }
        System.out.println(answer);
    }
}
/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