// editor2
#include <iostream>
#include <string>
using namespace std;
class customer{
    protected:
    string name, password;
    public :
    void diplay(){
        cin>>name>>password;}};
        class meter{
            protected:
            string role;
            public :
            void display1 (){
                cin>>role;}};
                class bill : public meter , public customer{
                    public :
                    void result (){
                        if(name.empty()||password.empty()||role.empty()){
                            cout<<name<<endl<<role;
                        }
                    }
                };
                int main(){
                    bill b;
                    b. display();
                    b. display1();
                    b. result();
                    return 0;
                }