using System;
public class Program
{
public static void Main()
Console.WriteLine("Wuwedete 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);