#include <iostream>
struct A
{
    A() { std::cout << "A "; }
};
struct B
{
    B() { std::cout << "B "; }
};
struct X : virtual public A, private B
{
    X() { std::cout << "X "; }
};
struct Y : virtual public A, private B
{
    Y() { std::cout << "Y "; }
};
struct Z : public Y, public X
{
    Z() { std::cout << "Z "; }
};
;

int main()
{
    Z z;
}