public class Main {

    public static void main(String[] args) {

    Bus ai = new Bus(15,10,20,30);
        System.out.println( ai.getPetrolAmount());
        System.out.println(ai.getMaxPeople());
        System.out.println(ai.getPeopleCount());
        ai.arrive();
        System.out.println(ai.leave());




    }
}

public class Base {
    protected static int people_on_base;
    protected static int vechiles_on_base;
    protected static double  petrol_on_base;
    protected static double  goods_on_base;
}

public class Vechile extends Base {
    protected double petrol_amount;
    protected double tank_volume;

    Vechile(double petrol_amount, double tank_volume){
        this.petrol_amount = petrol_amount;
        this.tank_volume = tank_volume;
    };

    public double getTankVolume(){
        return tank_volume;
    }

    public double getPetrolAmount(){
        return petrol_amount;
    }

    public void arrive(){
        super.vechiles_on_base++;
        super.people_on_base++;
        petrol_amount = petrol_amount - 10;
    }

    public boolean leave(){
        if(super.people_on_base-- < 0 || super.petrol_on_base < tank_volume - petrol_amount){
            return false;
        }else{
            super.people_on_base--;
            super.petrol_on_base = super.petrol_on_base - (tank_volume - petrol_amount);
            petrol_amount = tank_volume;
            return true;
        }
    }
}

public class Bus extends Vechile {
    private int people;
    private int max_people;

    Bus(int people, int max_people, double petrol, double max_petrol) {
        super(petrol, max_petrol);
        this.max_people = max_people;
        this.people = people;
    }

    ;

    public int getPeopleCount() {
        return people;
    }

    public int getMaxPeople() {
        return max_people;
    }

    public void arrive() {
        super.arrive();
        super.people_on_base = people_on_base + people;
        people = 0;
    }

    public boolean leave() {
        if (super.leave() == true) {
            if (super.people_on_base - (max_people - people) < 0) {
                people = super.people_on_base;
                return true;
            } else {
                super.people_on_base = super.people_on_base - (max_people - people);
                people = max_people;
                return true;
            }
        } else {
            return false;
        }

    }
}

public class Truck extends Vechile{
    private double load;
    private double max_load;

    Truck(double load, double max_load, double petrol, double max_petrol){
        super(petrol, max_petrol);
        this.load = load;
        this.max_load = max_load;
    };

    public double getCurrentLoad(){
        return load;
    }

    public double getMaxLoad(){
        return max_load;
    }

    public void arrive(){
        super.arrive();
        super.goods_on_base = goods_on_base + load;
        load = 0;
    }

    public boolean leave(){
        if(super.leave() == true){
            if(super.goods_on_base - (max_load - load) < 0){
                load = super.goods_on_base;
                return true;
            }else{
                super.goods_on_base = super.goods_on_base - (max_load - load);
                load = max_load;
                return true;
            }
        }else{
            return false;
        }
    }
}