import java.util.Scanner;

public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        while (sc.hasNext()) {

            double a = sc.nextDouble();
            double sum = a;

            for (int i = 2; i <= 10; i++) {

                if (i % 2 == 0) {
                    a *= 2;
                } else {
                    a /= 3;
                }

                sum += a;

            }

            System.out.println(sum);

        }

    }

}

Create : 0055