import java.util.Scanner;
public class Main{
    public static Scanner scn=new Scanner (System.in);
    public static void main(String []args){
        ans();
    }
    public static void ans(){
    int x=scn.nextInt();
    int a=(x/500 )*1000;
    int b=(x%500);
   b=b/5;
   b=b*5;
    System.out.print(a+b);

    
    }
}
  
/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