import java.util.Scanner;
import java.util.LinkedList;
import java.lang.Math;

class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        Long x = sc.nextLong();

        long c500 = x/500;
        long c5 = (x-c500*500)/5;
        long iei = 1000*c500 + 5*c5;

        System.out.print(iei);

    }
}
/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