import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    long L = sc.nextLong();
    long R = sc.nextLong();
    long mL = L%2019;
    long mR = R%2019;
    long out = 3000;
    if(R-L >= 2018 || mL > mR){
      System.out.println(0);
    } else {
      for (long i=mL; i<=mR-1; i++) {
        for (long j=i+1; j<=mR; j++) {
          if(out > (i*j)%2019){
            out = (i*j)%2019;
          }
        }
      }
      System.out.println(out);
    }
  }
}


/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