c++ - virtual public inheritance? Need help understanding code -

I have a question about virtual heritage. I am interested in this code 1000 (class "two") and not 3 ( Class "A") prints

Here is the code:

  #include & lt; Iostream & gt; using namespace std; Class A {protected: int number; Public: A (int a = 0) {number = a;}}; Class A: Virtual public A {Public: A (int A = 3) {number = a;} Zero print () {cout & lt; & Lt; Number & lt; & Lt; Endl;}}; Class two: Virtual public A {Public: Two (Int a = 1000) {number = a;} Zero print () {cout & lt; & Lt; Number & lt; & Lt; Endl; }}; Class B: Public One, Public Two {Public: Zero Print () {cout & lt; & Lt; Number & lt; & Lt; Endl; }}; Int main () {BA; a print(); }   
 
 
 The base classes are started in that order:  one < / Code> then  two . Virtual heritage means that they share the same frequency to  A , so there is only one variable  number .  
 returns  one  to 3 to  number , then  two  is started, it is allocated to 1000 Does. Therefore, after starting the entire object, this value ends with 1000.