#include <iostream>
#include <typeinfo>
using namespace std;

class a
{
                public:
                                virtual void r()
                                {
                                                cout<<"aaa"<<endl;
                                }
                                ~a()
                                {
                                                cout<<"~aaa"<<endl;
                                }
};
class b:public a
{
                public:
                                virtual void r()
                                {
                                                cout<<"bbb"<<endl;
                                }
                                ~b()
                                {
                                                cout<<"~bbb"<<endl;
                                }
};

int main(void)
{
                b l;
                a* pp=dynamic_cast<a*>(&l);
                pp->r();
                delete pp;
                pp=NULL;
                return 0;
}