gistfile1.txt

#include <iostream>

struct A{
	void f(){
		std::cout << "A" << std::endl;
	}
};
struct B: public virtual A{
	void f(){
		std::cout << "B" << std::endl;
	}
};
struct C: public virtual A{
	void f(){
		std::cout << "C" << std::endl;
	}
};
struct D: public B, public C{
	void main(){
		f();
	}
};

int main(){

	return 0;
}