import java.util.*; 

class Main{
public static void main(String[] args){
	Scanner sc=new Scanner(System.in);
        long l=sc.nextLong();
        long r=sc.nextLong();
		long min=l*(l+1)%2019;
    
 	if((r-l)>=2018){
    		System.out.println(0);
    	}else if((r-l)<(2019-l%2019)){
     		for(long e=l;e<r;e++){
              for(long f=e+1;f<=r;f++){
            	 min=Math.min(min,e*f%2019);
              }
              if(min==0){break;}
            }
      	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