import java.util.Scanner;
 
public class Main {
    static Scanner stdIn = new Scanner(System.in);
    public static void main(String[] args){
        int l = stdIn.nextInt();
        int r = stdIn.nextInt();
 
        int min = Integer.MAX_VALUE;
        for(int i=l; (i<=r-1 && i<l+2019); i++){
            for(int j=i+1; (j<=r && j<i+2020); j++){
                if(((long)i*j) % 2019 < min){
                    min = (int)(((long)i*j) % 2019);
                }
            }
        }
 
        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