#include <iostream.h>

class a{
static const char sccsid[];
public:
virtual void a::idout(){cerr<<a::sccsid<<endl;}
};
const char a::sccsid[]="@(#) A vn 1";

class b:public a{
static const char sccsid[];
public:
virtual void b::idout(){ cerr<<b::sccsid<<endl; this->a::idout();}
};
const char b::sccsid[]="@(#) B vn 1.0";

class c:public b{
static const char sccsid[];
public:
virtual void c::idout(){ cerr<<c::sccsid<<endl; this->b::idout(); }
};
const char c::sccsid[]="@(#) C vn 1.1";

class d:public b{
static const char sccsid[];
public:
virtual void d::idout(){ cerr<<d::sccsid<<endl; this->b::idout(); }
};
const char d::sccsid[]="@(#) D vn 1.1";


main()
{	c x; d y; b* z;
	
	cout<<"c:";
	x.idout();
	cout<<"d:";
	y.idout();
	cout<<"c:";
	z=&x; z->idout();
	cout<<"d:";
	z=&y; z->idout();

	return 0;
}