#include <iostream>
#include <string>
#include <vector>

using namespace std;


class Person {
public:
    Person(string const &occupation, string const &name)
            : occupation_(occupation), name_(name) {
    }

    string getName() const {
        return name_;
    }

    string getOccupation() const {
        return occupation_;
    }

    virtual void Walk(string const &destination) const {
        outInfo() << " walks to: " << destination << endl;
    }

protected:
    ostream &outInfo() const {
        return cout << occupation_ << ": " << name_;
    }

private:
    string const occupation_;
    string const name_;
};


class Student : public Person {
public:
    Student(string const &name, string const &favouriteSong)
            : Person("Student", name), favouriteSong_(favouriteSong) {
    }

    void Learn() const {
        outInfo() << " learns" << endl;
    }

    void SingSong() const {
        outInfo() << " sings a song: " << favouriteSong_ << endl;
    }

    void Walk(string const &destination) const override {
        Person::Walk(destination);
        SingSong();
    }

private:
    string const favouriteSong_;
};


class Teacher : public Person {
public:
    Teacher(string const &name, string const &subject)
            : Person("Teacher", name), subject_(subject) {
    }

    void Teach() const {
        outInfo() << " teaches: " << subject_ << endl;
    }

private:
    string const subject_;
};


class Policeman : public Person {
public:
    Policeman(string const &name) : Person("Policeman", name) {}

    void Check(Person const &person) const {
        outInfo() << " checks " << person.getOccupation() << ". "
              << person.getOccupation() << "'s name is: " << person.getName() << endl;
    }
};


void VisitPlaces(Person const &person, vector<string> const &places) {
    for (auto const &place: places) {
        person.Walk(place);
    }
}


int main() {
    Teacher t("Jim", "Math");
    Student s("Ann", "We will rock you");
    Policeman p("Bob");

    VisitPlaces(t, {"Moscow", "London"});
    p.Check(s);
    VisitPlaces(s, {"Moscow", "London"});
    return 0;
}