structadd

                if (command.StartsWith("add"))
                {
                    var commandParts = command.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
                    if (commandParts.Length < 3)
                        Console.WriteLine($"Wrong arguments count.");
                    else
                    {
                        if (Complex.TryParse(commandParts[1], out Complex c1) &&
                            Complex.TryParse(commandParts[2], out Complex c2))
                        {
                            var result = c1.Add(c2);
                            Console.WriteLine(result.ToString());
                        }
                    }
                }
                else if