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