interface Jing{
	void jing();
}
interface Zhu{
	void zhu();
}
abstract class Person{
	public abstract void speak();
	}
class Son extends Person implements Jing{
	@Override
	public void speak(){
		System.out.println("就说话");
	}
	@Override
	public void jing(){
		System.out.println("静静");
	}
}
class Demo{
	public static void main(String[] args){
		Person a=new Son();
		a.speak();
	}
}