@Override
    public void run() {
        Scanner sc = new Scanner(System.in);
        while (true) {
            int choice;
            while (true) {
                showMenu();
                try {
                    String input = sc.next();
                    choice = Integer.parseInt(input);
                    break;
                } catch (NumberFormatException ne) {    //handle invalid input
                    System.out.print("Invalid choice, choose again: ");
                }
            }
            switch (choice) {
                case 1:
                    checkMembership();
                    break;
                case 2:
                    memberManager.printMembers();
                    break;
                case 3:
                    addMember();
                    break;
                case 4:
                    deleteMember();
                    break;
                default:
                    return;
            }
        }
    }