import java.util.*;
 
public class Main {
  public static void main (String[] arg) {
    Scanner scan = new Scanner(System.in);
    long L = scan.nextLong();
    long R = scan.nextLong();
    long min = 2019;
    
    if(R-L >= 2018-(L%2019)){
      System.out.println(0);
      return;
    } else {
      for(Long i = L; i < R; i++){
        for(int j = 1; j <= R-i; j++){
          if((i*(i+j))%2019 < min){
            min = (i*(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