有如下程序:
#include<iostream>
using namespace std;
class ONE
public:
virtual void f()cout<<"1";
;
class TWO:public ONE
public:
TWO()cout<<"2";
;
class THREE:public TWO
public:
vurtual void f() TOW::f();cout<<"3";
;
int main()
ONE aa,*p;
TWO bb;
THREE cc;
p=&cc;
p->f();
return 0;
执行该程序的输出结果是______。