public class Main {

    class Engine{
        private int cylinders, horsepower, torque;
        private String manufacturer;
    }

    class Transport {
        protected String brand, model, color, interior, ownerName, modifications, specifications;
        protected int seats, startYear, mileage, mass;
    }

    class AirTransport extends Transport {
        protected int maxHeight, maxDistance;
    }

    class Helicopter extends AirTransport {
        private int blades;
        private String rotorsType;
        private Engine engine;
    }

    class Airplane extends AirTransport {
        private String airplaneClass;
        private Engine[] engines;
        private int landings;
    }

    class SeaTransport extends Transport {
        protected int volumeDisplacement, massDisplacement, normalDisplacement, fullDisplacement;
        protected Engine engine;
    }

    class Trailer extends Transport {
        private String trailerType;
    }
    class GroundTransport extends Transport {
        protected int wheels, fuelTankVolume, highwayConsumption, cityConsumption, gears;
        protected String wheelDrive, gearboxType, gearboxManufacturer, soundSystem;
        protected Engine engine;
        protected boolean leftSided;
    }

    class PassengerCar extends GroundTransport {
        private String bodyType, rimsType, tyresType, assembly, equipment;
        private int rimsRadius, acceleration;
        private Trailer trailer;
    }

    class Truck extends GroundTransport {
        private Trailer trailer;
        private String trailerConnection;
    }
    public static void main(String[] args) {
        System.out.println("Hello world!");
    }
}