import java.util.*;
 
public class Main {
    public static void main(String[] args)
    {
        Scanner s = new Scanner(System.in);
        int X = s.nextInt();
        int fiveHundred = X/500;
        X -= fiveHundred*500;
        int five = X/5;
        System.out.println(fiveHundred*1000+five*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