Transfer_of_fighters

namespace Transfer_of_fighters
{
    internal class Program
    {
        static void Main(string[] args)
        {
            Barracks barracks = new Barracks();

            barracks.ShowSoldersInAllSquads();

            barracks.TransefSolders();

            barracks.ShowSoldersInAllSquads();
        }
    }

    class Solder
    {
        public Solder(string secondNname)
        {
            SecondName = secondNname;
        }

        public string SecondName { get; private set; }
    }

    class Barracks
    {
        private List<Solder> _assaultSquad = new List<Solder>();
        private List<Solder> _defensiveSquad = new List<Solder>();

        public Barracks()
        {
            _assaultSquad.Add(new Solder("Иванов"));
            _assaultSquad.Add(new Solder("Мартьянов"));
            _assaultSquad.Add(new Solder("Белов"));
            _assaultSquad.Add(new Solder("Кравцов"));
            _assaultSquad.Add(new Solder("Белобров"));
            _assaultSquad.Add(new Solder("Царев"));

            _defensiveSquad.Add(new Solder("Петров"));
            _defensiveSquad.Add(new Solder("Бакуров"));
            _defensiveSquad.Add(new Solder("Богданов"));
            _defensiveSquad.Add(new Solder("Саликов"));
            _defensiveSquad.Add(new Solder("Комаров"));
        }

        public void ShowSoldersInAllSquads()
        {
            Console.WriteLine("Бойцы наступательного отряда:\n");

            ShowSolders(_assaultSquad);

            Console.WriteLine("\nБойцы оборонительного отряда:\n");

            ShowSolders(_defensiveSquad);
        }

        public void TransefSolders()
        {
            char firsLetterSecondName = 'Б';

            _defensiveSquad = _defensiveSquad.Concat(_assaultSquad.Where(solder => solder.SecondName[0] == firsLetterSecondName)).ToList();

            _assaultSquad = _assaultSquad.OrderBy(solder => solder.SecondName)
                            .SkipWhile(solder => solder.SecondName[0] == firsLetterSecondName).ToList();
        }

        private void ShowSolders(List<Solder> solders)
        {
            foreach (Solder solder in solders)
            {
                Console.WriteLine($"Фамилия - {solder.SecondName}");
            }
        }
    }
}