using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("vuvedete chislo");

        double a=double.Parse(Console.ReadLine());

        Console.Write("S=");

        double sum=0;

        double k;

        for (double i=1; i<=a; i++)

        {

            sum=sum+i/(i+1);

            k=i+1;

            Console.Write("{0}/{1}+", i, k);

        }

        Console.Write("="+sum);

    }

}