
import java.util.*;
public class Main {
	public static void main ( String [] args) {
		Scanner input = new Scanner (System.in);
		int x = input.nextInt();
		int h = (x/500)*1000;
		int f = ((x%500)/5)*5;
		System.out.println(h+f);
		
	}

}
/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