Построить иерархию классов Республика, монархия, королевство, государство

#include <iostream>
#include <string>
 
using namespace std;
 
class State {
protected:
    string name;
    int population;
 
public:
    State(string name, int population) : name(name), population(population) {}
    string getName() const { return name; }
    int getPopulation() const { return population; }
};
 
class Republic : public State {
protected:
    string president;
 
public:
    Republic(string name, int population, string president)
        : State(name, population), president(president) {}
    string getPresident() const { return president; }
    void setPresident(const string &president) { this->president = president; }
};
 
class Monarchy : public State {
protected:
    string monarch;
 
public:
    Monarchy(string name, int population, string monarch)
        : State(name, population), monarch(monarch) {}
    string getMonarch() const { return monarch; }
    void setMonarch(const string &monarch) { this->monarch = monarch; }
};
 
class Kingdom : public Monarchy {
protected:
    string king;
 
public:
    Kingdom(string name, int population, string king)
        : Monarchy(name, population, king), king(king) {}
    string getKing() const { return king; }
    void setKing(const string &king) { this->king = king; }
};
 
int main() {
    Republic republic("Republic of Example", 1000000, "President Example");
    Kingdom kingdom("Kingdom of Example", 2000000, "King Example");
 
    cout << "Republic: " << republic.getName() << ", Population: " << republic.getPopulation() << ", President: " << republic.getPresident() << endl;
    cout << "Kingdom: " << kingdom.getName() << ", Population: " << kingdom.getPopulation() << ", King: " << kingdom.getKing() << endl;
 
    return 0;
}