マルチ継承の場合、複数のベースクラスに同じ型の虚関数が存在しますが、どうすればいいですか?

#include "stdafx.h"

#include<iostream>



using namespace std;



class A{

public:

    virtual void show(){

        cout<<"in classA"<<endl;

    }

    virtual ~A(){} 

};



class B{

public:

    virtual void show(){

        cout<<"in classB"<<endl;

    }

    virtual ~B(){} 

};



class MidA:public A{

public:

    virtual void realshowA() = 0;

    virtual void show(){

        realshowA();

    }

//    virtual ~MidA(){} 

};

class MidB:public B{

public:

    virtual void realshowB() = 0;

    virtual void show(){

        realshowB();

    }

//    virtual ~MidB(){}

};



class Derive :public MidA,public MidB{

public:

    void realshowA(){

        cout<<"realshow in classA"<<endl;

    }

    void realshowB(){

        cout<<"realshow in classB"<<endl;

    }

//    virtual ~Derive(){}

};





int main(int argc,char * argv){

    A *pa= new Derive;

    B *pb= new Derive;

    pa->show();

    pb->show();



    delete pa;

    delete pb;



    return 0;

}