#include <iostream>
#include <memory>


using namespace std;

class Request {
public:
    int days;
    enum {
        PERSONAL_LEAVE,
        ANNUAL_LEAVE,
    } reason;
};


class Handler {
    shared_ptr<Handler> next;
public:
    void next_handle(const Request& r) {
        if (!next) {
            cout << "Request unhandled" << endl;
        }
        next->handle(r);
    }

    void set_next(shared_ptr<Handler> n) {
        next = n;
    }

    virtual void handle(const Request& r) = 0;
};


class LeaderHandler : public Handler {
public:
    virtual void handle(const Request& r) override {
        if (r.days < 3) {
            cout << "Leader: OK" << endl;
        } else {
            next_handle(r);
        }
    }
};


class SupervisorHandler : public Handler {
public:
    virtual void handle(const Request& r) override {
        if (r.days < 7 || r.reason == Request::ANNUAL_LEAVE) {
            cout << "Supervisor: OK" << endl;
        } else {
            next_handle(r);
        }
    }
};

class ManagerHandler : public Handler {
public:
    virtual void handle(const Request& r) override {
        cout << "Manager: OK" << endl;
    }
};

int main() {
    auto lh = make_shared<LeaderHandler>();
    auto sh = make_shared<SupervisorHandler>();
    auto mh = make_shared<ManagerHandler>();

    lh->set_next(sh);
    sh->set_next(mh);

    Request r1 {1, Request::PERSONAL_LEAVE};
    Request r2 {4, Request::ANNUAL_LEAVE};
    Request r3 {10, Request::PERSONAL_LEAVE};

    lh->handle(r1);
    lh->handle(r2);
    lh->handle(r3);
}