写出下面程序的执行结果：

#include<iostream>

using namespace std;

class AA{

int a;

public :

AA(int i){a=i;cout<<"AA="<<a<<"
";}

virtual ~AA( ){cout<<"~AA="<<a<<"
";}

};

class BB:public AA{

int b;

public :

BB(int i,int j):AA(i){b=j;cout<<"BB="<<b<<"
";}

~BB( ){cout<<"~BB="<<b<<"
";}

};

int  main( )

{AA *pa=new AA(8);  delete pa;

AA*pb=new  BB(6,9);  delete pb;

 return 0;

}