#include<iostream.h>
class a {};
class b{};
class c:public a{
virtual void fun()=0;
};
class d:public b,public c{};
int main(){
cout<<"sizeof(a)"<<sizeof(a)<<endl;
cout<<"sizeof(b)"<<sizeof(b)<<endl;
cout<<"sizeof(c)"<<sizeof(c)<<endl;
cout<<"sizeof(d)"<<sizeof(d)<<endl;
return 0;
}