若有以下程序：#include ＜iostream＞using namespace std;class Base{public:void who(){ cout＜＜"Base"＜＜end1;}};class Derivedl: public Base{public:void who() { cout＜＜"Derived"＜＜end1; }};int main(){ Base *p; Derived1 obj1; p=&obj1; p-＞who(); return 0;}则该程序运行后的输出结果是 【9】 。