import java.util.Scanner;

public class Main{

  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int S = sc.nextInt();
    int totalHappy = 0;
    totalHappy  = totalHappy + ((S/500) * 1000);
    S = S%500;
    totalHappy = totalHappy + ((S/5) *5);
    S = S%5;
    System.out.println(totalHappy);
  }
  
}

/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