import java.util.Scanner;

public class Main{
    public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
	int x = sc.nextInt();

	int c500 = x/500;
	int c5 = (x%500)/5;

	System.out.print(c500*1000 + c5*5);
    }
} import java.util.Scanner; Scanner java.util public class Main{
    public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
	int x = sc.nextInt();

	int c500 = x/500;
	int c5 = (x%500)/5;

	System.out.print(c500*1000 + c5*5);
    }
} Main public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
	int x = sc.nextInt();

	int c500 = x/500;
	int c5 = (x%500)/5;

	System.out.print(c500*1000 + c5*5);
    } main {
	Scanner sc = new Scanner(System.in);
	int x = sc.nextInt();

	int c500 = x/500;
	int c5 = (x%500)/5;

	System.out.print(c500*1000 + c5*5);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int x = sc.nextInt(); x sc.nextInt() sc.nextInt sc int c500 = x/500; c500 x/500 x 500 int c5 = (x%500)/5; c5 (x%500)/5 (x%500) x 500 5 System.out.print(c500*1000 + c5*5) System.out.print System.out System System.out c500*1000 + c5*5 c500*1000 c500 1000 c5*5 c5 5 String[] args args public class Main{
    public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
	int x = sc.nextInt();

	int c500 = x/500;
	int c5 = (x%500)/5;

	System.out.print(c500*1000 + c5*5);
    }
} public class Main{
    public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
	int x = sc.nextInt();

	int c500 = x/500;
	int c5 = (x%500)/5;

	System.out.print(c500*1000 + c5*5);
    }
} Main
import java.util.Scanner;

public class Main{
    public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
	int x = sc.nextInt();

	int c500 = x/500;
	int c5 = (x%500)/5;

	System.out.print(c500*1000 + c5*5);
    }
}
