import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long D = sc.nextLong();
        long d = D*108;
        String A = String.valueOf(d);
        String B = A.substring(0,A.length()-2)+"."+A.substring(A.length()-2);
        System.out.println(B);
    }
}