#include <iostream>
#include <string>
using namespace std;

class base
{
    public:
        base(int p1=1, int p2=2, int p3=3) : pub(p1), pri(p2), pro(p3) {}
        int pub;
    private:
        int pri;
    protected:
        int pro;
};

class derived_private : private base
{
    public:
        using base::pub;
//        using base::pri;
        using base::pro;
        void print_pri() 
        { 
            cout << "pub:" << pub << endl;
            cout << "pro:" << pro << endl;
        }
};

int main()
{
    base b;
    cout << b.pro << endl;

    derived_private d;
    cout << d.pub << endl;
    cout << d.pro << endl;  这都可以？
}