#include <iostream>
using namespace std;

class TV {
protected:
    int channel;
    int volume;

public:
    TV() {
        channel = 1;
        volume = 10;
    }

    void showInfo() {
        cout << "현재 채널: " << channel << endl;
        cout << "현재 볼륨: " << volume << endl;
    }
};

class Remote : public TV {
public:
    void changeChannel(int ch) {
        channel = ch;
        cout << "채널이 " << channel << "번으로 변경되었습니다." << endl;
    }

    void volumeControl(int v) {
        volume += v;
        if (volume < 0) volume = 0;
        if (volume > 100) volume = 100;
        cout << "볼륨이 " << volume << "으로 조절되었습니다." << endl;
    }
};

int main() {
    Remote r;

    cout << "[Before]" << endl;
    r.showInfo();

    int ch, vol;

    cout << "\n[After]" << endl;
    r.showInfo();

    return 0;
}