  import java.util.Scanner;

  public class Main {

    public static void main(String[] args) {
      int x = Integer.parseInt(new Scanner(System.in).nextLine());
      int c500 = x/500;
      int r500 = x%500;
      int c5 = r500/5;
      System.out.printf("%d\n",c500*1000+c5*5);
    }
  }
/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