
import java.util.Scanner;

public class Main{
	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);

		Long n 	   = Long.parseLong(scanner.nextLine());
		Long count  = (long)Math.floor(n / 500.0);
		Long tcoun  = (long)Math.floor((n - 500 * count) / 5.0);

		System.out.println(count * 1000 + tcoun * 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