import java.util.Scanner;
public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		long x = scan.nextLong();
		int uresi500 = 1000;
		int uresi5 = 5;
		int count500 = 0;
		int count5 = 0;


		while(x >= 500) {
			x -= 500;
			count500++;
		}

		while(x >= 5){
			x -= 5;
			count5++;
		}

		int re = count500*uresi500 + count5*uresi5;

		System.out.println(re);

		scan.close();

	}

}

/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