import java.util.Scanner;

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

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