import java.util.Scanner;

public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int X=sc.nextInt();
    int a=X%500;
    int Y=X-a;
    int N=Y/500;
    int b=a%5;
    int Z=a-b;
    int M=Z/5;
    System.out.println((1000*N)+(5*M));
  }
}
/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