import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		int haveyen = sc.nextInt();
		int money500 = haveyen / 500;
		int happy500 = money500 * 1000 ;
		int money5 = (haveyen - (money500 * 500)) / 5;
		int happy5 = money5 * 5;

		System.out.println(happy500 + happy5);
	}
}
/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