static void Main(string[] args)
        {
            Banking bank = new Banking();

            bank.AccountDefault();
            MainMenu(bank);
            Console.ReadKey();
        }
        static void ClientMenu(Banking bank, int index)
        {
            Console.WriteLine("1. Show info about client\n2. Add money to account\n3. Charge off money from account\n4. Transfer money\n5. Money box\n6. Deposit\n0. Back");
            int select = Convert.ToInt32(Console.ReadLine());

            switch (select)
            {
            case 0:
                MainMenu(bank);
                break;

            case 1:
                bank[index].ShowFullInfo();
                ClientMenu(bank, index);
                break;

            case 2:
                Console.Write("Please enter sum, what you wanna add:");
                int sum = Convert.ToInt32(Console.ReadLine());
                bank[index].RefillSum(sum);
                ClientMenu(bank, index);
                break;

            case 3:
                Console.Write("Please enter sum, what you wanna charge off:");
                int chargeoff = Convert.ToInt32(Console.ReadLine());
                bank[index].ChargeOffSum(chargeoff);
                ClientMenu(bank, index);
                break;

            case 4:
                Console.Write("Please enter sum, what you wanna transfer:");
                int sumTransfer = Convert.ToInt32(Console.ReadLine());
                if (bank[index].CheckSum(sumTransfer))
                {
                    bank[index].ChargeOffSum(sumTransfer);
                    bank.Transfer(sumTransfer);
                }
                ClientMenu(bank, index);
                break;

            case 5:
                bank[index].AddMoneyBoxRate();
                ClientMenu(bank, index);
                break;

            case 6:
                bank[index].AddDepositSum();
                ClientMenu(bank, index);
                break;

            default:
                ClientMenu(bank, index);
                break;
            }
        }
        static void MainMenu(Banking bank)
        {
            Console.WriteLine("1. Add client\n2. Delete client\n3. Show clients\n4. Search client\n5. Sort clients\n0. Exit");
            int select = Convert.ToInt32(Console.ReadLine());

            switch (select)
            {
            case 0: break;

            case 1:
                bank.AddClient();
                MainMenu(bank);
                break;

            case 2:
                Console.Write("Please enter the index of client what you wanna delete: ");
                int index = Convert.ToInt32(Console.ReadLine());
                bank.DeleteClient(index);
                MainMenu(bank);
                break;

            case 3:
                bank.ShowClients();
                SelectMenu(bank);
                break;

            case 4:
                bank.SearchClient();
                MainMenu(bank);
                break;

            case 5:
                bank.SortClient();
                MainMenu(bank);
                break;

            default:
                Console.WriteLine("Wrong select number! Please try again!\n");
                MainMenu(bank);
                break;
            }
        }
        static void SelectMenu(Banking bank)
        {
            Console.Write("Please enter index of client, what you wanna choose\n(If you wanna back please enter 0): ");
            int index = Convert.ToInt32(Console.ReadLine());

            if (index == 0)
            {
                MainMenu(bank);
            }
            else
            {
                if (bank.CheckClient(index))
                {
                    ClientMenu(bank, index - 1);
                }
                else
                {
                    MainMenu(bank);
                }
            }
        }