import java.util.Scanner;

public class Main {


    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int yen = scanner.nextInt();
        int divValue, modValue, totalHp;

        divValue = yen / 500;
        totalHp = divValue * 1000;
        modValue = yen % 500;

        if (modValue != 0) {
            divValue = modValue / 5;
            totalHp = totalHp + divValue * 5;
        }
        System.out.println(totalHp);


    }
}
/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