有如下类声明: class MyBASE int k; public: void set(int n) k=n; int get()const return k; ; class MyDERIVED: protected MyBASE Protected: int j; public: void set(int m,int n)MyBASE:: set(m);j=n; int get () const return MyBASE:: get ()+j; ; 则类MyDERIVED 中保护的数据成员和成员函数的个数是______ 。