public static void Main(string[] args)
        {
            if (args.Length != 2)
            {
                Console.WriteLine("Usage: CopyDirectoryStructure <source root directory path> <target root directory path>");
                return;
            }

            if (!Directory.Exists(args[0]))
            {
                Console.WriteLine("The source directory {0} does not exist", args[0]);
                return;
            }

            if (Directory.Exists(args[1]))
            {
                Console.WriteLine("The target directory {0} exists and I don't overwrite", args[1]);
                return;
            }


            var program = new CopyDirectoryStructure(args[0], args[1]);

            program.Go();
        }
        public static void Main(string[] args)
        {
            if(args.Length != 2)
            {
                Console.WriteLine("Usage: CopyDirectoryStructure <source root directory path> <target root directory path>");
                return;
            }

            if(!Directory.Exists(args[0]))
            {
                Console.WriteLine("The source directory {0} does not exist", args[0]);
                return;
            }

            if (Directory.Exists(args[1]))
            {
                Console.WriteLine("The target directory {0} exists and I don't overwrite", args[1]);
                return;
            }

            var program = new CopyDirectoryStructure(args[0], args[1]);

            program.Go();
        }