public static void SecondDemo()
        {
            IMathematicalAdapter adapter = null;

            //Let emulate the decision where the choice of using the underlying system is made
            Console.WriteLine("Enter which library you wanna use to do operation {1,2}");
            int x = Console.Read();

            if (x == '1')
            {
                //Let us choose to use Library one to do something
                adapter = new AdapterOne();
            }
            else if (x == '2')
            {
                //Let us choose to use Library two to do something
                adapter = new AdapterTwo();
            }

            //Just do the operation now
            adapter.PerformOperation();
            Console.WriteLine();
        }
            static void Main(string[] args)
            {
                IAdapter adapter = null;

                //Let emulate the decision where the choice of using the underlying system is made
                Console.WriteLine("Enter which library you wanna use to do operation {1,2}");
                int x = Console.Read();

                if (x == '1')
                {
                    //Let us choose to use Library one to do something
                    adapter = new AdapterOne();
                }
                else if (x == '2')
                {
                    //Let us choose to use Library two to do something
                    adapter = new AdapterTwo();
                }

                //Just do the operation now
                adapter.Do();
                Console.ReadKey();
            }