다음 Java 프로그램의 실행 결과를 쓰시오.

public class Main {
    public static void main(String[] args) {
        Base a = new Derived();
        Derived b = new Derived();
        System.out.print(a.getX() + a.x + b.getX() + b.x);
    }
}

class Base {
    int x = 3;
    int getX() { return x * 2; }
}

class Derived extends Base {
    int x = 7;
    int getX() { return x * 3; }
}