public void say() {        

         System.out.println("我是父亲");

}     

    public void haveMoney() { 

        System.out.println("我有115万的存款");    }

 } 

 class Son extends Father { 

    public void say() { 

       System.out.println("我是儿子");

}    

    public void hobby() {

        System.out.println("我喜欢打篮球");   

} 

} 

class Demo {

    public static void main(String args[]) {                 Father a = new Son(); 

        a.say();       

        a.haveMoney();      

        a.hobby();    

  }

}

Class Counter {

Static int num = 0;

Public void setNum (int num) {

This.num += num; System.out.println (num);

}

}

则执行代码

Counter c1 = new Counter(); 

Counter c2 = new Counter();

 Counter c3 = new Counter();

c1.setNum(1); 

c2.setNum(2); 

c3.setNum(3); 的结果是（ ）。