using System;

public class Program

{

    public static double MagicFunction(double s, int i)

    {

        Console.WriteLine(s.ToString());

        return s;

    }

    public static double Calc(double d, int i, ref double s)

    {

        if( i < 10)

        {           

            s = s + MagicFunction(d, i);

            return Calc( d /1.1, i + 1, ref s);

        }

        else

            return d;

    }   

    public static void Main()

    {

        double d = 10.0;

        double s = 0.0;

​

        double rd = Calc(10.0, 0, ref s);

        Console.WriteLine(rd.ToString());

        Console.WriteLine(s.ToString());

    }

}