// editor2
#include<iostream>
#include<string>
using namespace std;
class customer{
    protected:
    string name,password;
    public:
    void display(){
        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.res();
            return 0;
        }