import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		int x = sc.nextInt();

		System.out.println(x/500 * 1000 + (x - x / 500 * 500) / 5 * 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();

		System.out.println(x/500 * 1000 + (x - x / 500 * 500) / 5 * 5);
	}
} Main public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		int x = sc.nextInt();

		System.out.println(x/500 * 1000 + (x - x / 500 * 500) / 5 * 5);
	} main {

		Scanner sc = new Scanner(System.in);

		int x = sc.nextInt();

		System.out.println(x/500 * 1000 + (x - x / 500 * 500) / 5 * 5);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int x = sc.nextInt(); x sc.nextInt() sc.nextInt sc System.out.println(x/500 * 1000 + (x - x / 500 * 500) / 5 * 5) System.out.println System.out System System.out x/500 * 1000 + (x - x / 500 * 500) / 5 * 5 x/500 * 1000 x/500 x 500 1000 (x - x / 500 * 500) / 5 * 5 (x - x / 500 * 500) / 5 (x - x / 500 * 500) x x / 500 * 500 x / 500 x 500 500 5 5 String[] args args public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		int x = sc.nextInt();

		System.out.println(x/500 * 1000 + (x - x / 500 * 500) / 5 * 5);
	}
} public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		int x = sc.nextInt();

		System.out.println(x/500 * 1000 + (x - x / 500 * 500) / 5 * 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();

		System.out.println(x/500 * 1000 + (x - x / 500 * 500) / 5 * 5);
	}
}