import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);

		long money = scanner.nextLong();

		long coins500 = money / 500;
		long remainder = money % 500;
		long coins5 = remainder / 5;
		
		long maxHappy = coins500 * 1000 + coins5 * 5;
		System.out.println(maxHappy);

		scanner.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