import java.util.*;
import java.lang.*;
import java.io.*;
 
public class Main {
    public static void main(String args[]) {
		 Scanner sc = new Scanner(System.in);
		 int s = sc.nextInt();
		 int total = 0;
		 total += s/500 * 1000;
		 s %= 500;
		 total += s/5 *5;
		 System.out.println(total);
	}
}
/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