import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;

public class P12 {
    private String name;
    private int age;
    private PropertyChangeSupport propertyChangeSupport;

    public P12() {
        propertyChangeSupport = new PropertyChangeSupport(this);
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        String oldName = this.name;
        this.name = name;
        propertyChangeSupport.firePropertyChange("name", oldName, name);
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        if (age < 0) {
            throw new IllegalArgumentException("Age cannot be negative");
        }
        int oldAge = this.age;
        this.age = age;
        propertyChangeSupport.firePropertyChange("age", oldAge, age);
    }

    public void addPropertyChangeListener(PropertyChangeListener listener) {
        propertyChangeSupport.addPropertyChangeListener(listener);
    }

    public void removePropertyChangeListener(PropertyChangeListener listener) {
        propertyChangeSupport.removePropertyChangeListener(listener);
    }
}