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

class base {
	static int n;
public:
	base() {++n;}
	base(const base& another) {++n;}
	~base() {--n;}
	static int count() {return n;}
};

int base::n = 0;

class derived1: public base {
	//etc.
};

class derived2: public base {
	//etc.
};

int main()
{
	derived1 a, b, c;
	derived2 d;

	cout << "derived1::count " << derived1::count() << "\n"
		<< "derived2::count " << derived2::count() << "\n";
	return EXIT_SUCCESS;
}