
import java.util.Scanner;

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

		Scanner sc = new Scanner(System.in);

		int X = Integer.parseInt(sc.next());

		int ure = 0;

		while(X >= 500) {
			ure += (X / 500)*1000;
			X %= 500;

		}

		while(X >= 5) {
			ure += (X / 5)*5;
			X %= 5;

		}



		System.out.println(ure);

	}
}
/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