using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("n =");

        int n = int.Parse(Console.ReadLine());

        double s = 0;

        for(int i = 1; i <=n; i++)

        {

         s = s + 1.0/i;

        }

        Console.WriteLine("s = {0}",s);

        Console.ReadKey();

    }

}