#include <iostream>

class X {
   public:
      X() { std::cout << "X constructed" << std::endl; }
};
class Y {
   public:
      Y() { std::cout << "Y constructed" << std::endl; }
};
class Z {
   public:
      Z() : y(), x() {}
   private:
      X x;
      Y y;
};
int main() {
   Z z;
}