What will be printed out as a result of the following code execution?

#include <iostream>

using namespace std;

struct A { A() { cout << "A"; } };
struct B : A { B() { cout << "B"; } };
struct C : A { C() { cout << "C"; } };
struct D : B, C { D() { cout << "D"; } };

int main() {
  D d;
}