string test_board_2[] = {"X-XO",
                         "-XOO",
                         "--OX",
                         "X-O-"};
    int size_2 = 4;
    read_board_from_string(board, test_board_2, size_2);
    cout << count_unknown_squares(board, size_2) << endl;
    
    
    string test_board_4[] = {"X-O",
                             "OXO",
                             "-XX",};
    int size_4 = 3;
    read_board_from_string(board, test_board_4, size_4);
    cout << count_unknown_squares(board, size_4) << endl;