static List <IRobber> GetRobbers()
        {
            List <IRobber> operatives = new List <IRobber>()
            {
                new Hacker
                {
                    Name          = "Tim",
                    SkillLevel    = 35,
                    PercentageCut = 60,
                },
                new Hacker
                {
                    Name          = "BobPete",
                    SkillLevel    = 55,
                    PercentageCut = 10,
                },
                new Muscle
                {
                    Name          = "Sara",
                    SkillLevel    = 45,
                    PercentageCut = 25,
                },
                new Muscle
                {
                    Name          = "BobJoe",
                    SkillLevel    = 55,
                    PercentageCut = 10,
                },
                new LockSpecialist
                {
                    Name          = "Gus",
                    SkillLevel    = 25,
                    PercentageCut = 30,
                },
                new LockSpecialist
                {
                    Name          = "BobBob",
                    SkillLevel    = 55,
                    PercentageCut = 10,
                }
            };

            while (true)
            {
                Console.WriteLine($"Your contact list has {operatives.Count} entries.");
                Console.Write("Enter crew member's name to add to contact list: ");
                string name = Console.ReadLine();
                if (name == "")
                {
                    Console.WriteLine("------------------");
                    break;
                }

                int speciality = 0;
                while (true)
                {
                    Console.WriteLine(@"
1. Hacker (Disables alarms)
2. Muscle (Disarms guards)
3. Lock Specialist (Cracks vault)
                    ");
                    try
                    {
                        speciality = int.Parse(Console.ReadLine());
                        if (speciality > 0 && speciality < 4)
                        {
                            break;
                        }
                    }
                    catch
                    {
                        Console.WriteLine("Enter a number 1-3");
                    }
                }

                int skill = 0;
                while (true)
                {
                    Console.Write("Enter crew member's skill (1-100): ");
                    try
                    {
                        skill = int.Parse(Console.ReadLine());
                        if (skill > 0 && skill <= 100)
                        {
                            break;
                        }
                    }
                    catch
                    {
                        Console.WriteLine("Enter a number 1-100");
                    }
                }

                int percent = 0;
                while (true)
                {
                    Console.Write("Enter crew member's percentage cut (1-100): ");
                    try
                    {
                        percent = int.Parse(Console.ReadLine());
                        if (percent > 0 && percent <= 100)
                        {
                            break;
                        }
                    }
                    catch
                    {
                        Console.WriteLine("Enter a number 1-100");
                    }
                }

                switch (speciality)
                {
                case 1:
                    var Hacker = new Hacker
                    {
                        Name          = name,
                        SkillLevel    = skill,
                        PercentageCut = percent
                    };
                    operatives.Add(Hacker);
                    break;

                case 2:
                    var Muscle = new Muscle
                    {
                        Name          = name,
                        SkillLevel    = skill,
                        PercentageCut = percent
                    };
                    operatives.Add(Muscle);
                    break;

                case 3:
                    var LockSpecialist = new LockSpecialist
                    {
                        Name          = name,
                        SkillLevel    = skill,
                        PercentageCut = percent
                    };
                    operatives.Add(LockSpecialist);
                    break;
                }
                Console.WriteLine("------------------");
            }
            return(operatives);
        }