#include <iostream>

using namespace std;

class A { public: int x; };
class B1 : public A {};
class B2 : public A {};
class C : public B1, public B2 {};

int main() {
  C c;
  c.B1::x = 3; c.B2::x = 7;
  cout << c.B1::x << " " << c.B2::x
       << endl;
}
