public static string LevelWorker(Worker.LEVELWORKER level)
        {
            switch (level)
            {
            case Worker.LEVELWORKER.ONE:
                return("1/7");

            case Worker.LEVELWORKER.TWO:
                return("2/7");

            case Worker.LEVELWORKER.THREE:
                return("3/7");

            case Worker.LEVELWORKER.FOUR:
                return("4/7");

            case Worker.LEVELWORKER.FIVE:
                return("5/7");

            case Worker.LEVELWORKER.SIX:
                return("6/7");

            default:
                return("7/7");
            }
        }
        public void AddOfficial()
        {
            int choice;

            do
            {
                Console.WriteLine("Who do you want to add : ");;
                Console.WriteLine("1. Worker\n2. Engineer\n3. Staff");
                Console.Write("Your choice : ");
                choice = int.Parse(Console.ReadLine());
                if (choice < 1 && choice > 3)
                {
                    Console.WriteLine("Enter your choice again");
                }
            } while (choice < 1 && choice > 3);

            string name;
            int    yearOfBirth;
            GENDER gender;
            string address;
            int    choiceGender;

            Console.Write("Name: ");
            name = Console.ReadLine();
            Console.Write("Year of birth: ");
            yearOfBirth = int.Parse(Console.ReadLine());
            do
            {
                Console.Write("Gender: 1. Female  2. Male ");
                choiceGender = int.Parse(Console.ReadLine());
                if (choiceGender != 1 && choiceGender != 2)
                {
                    Console.WriteLine("Enter gender again");
                }
            } while (choiceGender != 1 && choiceGender != 2);

            if (choiceGender == 1)
            {
                gender = GENDER.FEMALE;
            }
            else
            {
                gender = GENDER.MALE;
            }

            Console.Write("Address: ");;
            address = Console.ReadLine();

            switch (choice)
            {
            case 1:
                int level;
                do
                {
                    Console.Write("Level (1-7): ");
                    level = int.Parse(Console.ReadLine());
                    if (level < 1 && level > 7)
                    {
                        Console.WriteLine("Enter level again");
                    }
                } while (level < 1 && level > 7);
                Worker.LEVELWORKER levelOfWorker = (Worker.LEVELWORKER)level;
                Worker             aWorker       = new Worker(name, yearOfBirth, gender, address, levelOfWorker);
                officialList.Add(aWorker);
                break;

            case 2:
                Console.Write("Profession: ");
                string   profession = Console.ReadLine();
                Engineer anEngineer = new Engineer(name, yearOfBirth, gender, address, profession);
                officialList.Add(anEngineer);
                break;

            case 3:
                Console.Write("Affair: ");
                string affair = Console.ReadLine();
                Staff  aStaff = new Staff(name, yearOfBirth, gender, address, affair);
                officialList.Add(aStaff);
                break;
            }
        }