getting following error org.hibernate.AnnotationException: No identifier specified for entity: inheritance_tutorial17.TwoWheeler

when i am running following code i am getting following error...

package inheritance_tutorial17;

import javax.persistence.GeneratedValue; import javax.persistence.Id;

public class Vehicle {

@Id @GeneratedValue
private int id;
private String name;

public int getId() {
    return id;
}
public void setId(int id) {
    this.id = id;
}
public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}

}

package inheritance_tutorial17;

import javax.persistence.Entity;

@Entity public class TwoWheeler extends Vehicle {

private String sterringHandel;

public String getSterringHandel() {
    return sterringHandel;
}

public void setSterringHandel(String sterringHandel) {
    this.sterringHandel = sterringHandel;
}

}

package inheritance_tutorial17;

import javax.persistence.Entity;

@Entity public class FourWheeler extends Vehicle {

private String steeringWheel;

public String getSteeringWheel() {
    return steeringWheel;
}

public void setSteeringWheel(String steeringWheel) {
    this.steeringWheel = steeringWheel;
}

}

package inheritance_tutorial17;

import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration;

public class Test {

/**
 * @param args
 */
public static void main(String[] args) {

    Vehicle vehicle=new Vehicle();
    vehicle.setName("CAR");

    TwoWheeler two=new TwoWheeler();
    two.setName("BIKE");
    two.setSterringHandel("STEERING HADEL");

    FourWheeler four=new FourWheeler();
    four.setName("Porsche");
    four.setSteeringWheel("STEERING WHEEL");

    SessionFactory sessionfactory=new Configuration().configure().buildSessionFactory();
    Session session= sessionfactory.openSession();
    session.beginTransaction();
    session.save(vehicle);
    session.save(two);
    session.save(four);
    session.getTransaction().commit();
    session.close();
}

}