import java.util.Scanner;
class Main {
  public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    long money , goen ,gohyaku;
    money = sc.nextInt();
    goen = (money % 500) / 5 * 5;
    gohyaku = (money / 500) *1000;
    System.out.println(goen + gohyaku);
  }
}

/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