class AirCraftCabinLoading:
    def __init__(self):
        self.aircraft=[]
        for i in range(10):
            self.aircraft.push({
                "unavailableSeatsRight":0,
                "unavailableSeatsLeft":0,
                "takenSeatsRight":0,
                "takenSeatsLeft":0,
                "passengerOrGroupIds":{}
            })

    def _place_passengers_in_row(self,row,numberOfPassengers,id):
        for i in range(numberOfPassengers):
            if (row["takenSeatsRight"]>row["takenSeatsLeft"]):
                row["takenSeatsLeft"]+=1
            else:
                row["takenSeatsRight"]+=1
        row["passengerOrGroupIds"][id]=numberOfPassengers

    def _remove_passengers_in_row(self,row,id):
        numberOfPassengers=row["passengerOrGroupIds"][id]
        for i in range(numberOfPassengers):
            if (row["takenSeatsRight"]>row["takenSeatsLeft"]):
                row["takenSeatsLeft"] -= 1
            else:
                row["takenSeatsRight"]-=1


    def place_passengers(self,numberOfPassengers,passenger_or_group_id):
        if (numberOfPassengers>4)
            raise Exception("No more than 4 passengers are allowed in a group");
        for i in [[5,4],[6,3],[7,2],[8,1],[9,0]]:
            first_row=self.aircraft[i[0]]
            second_row=self.aircraft[i[1]]
            seats_available_first_row=4-first_row["takenSeatsLeft"]-first_row["takenSeatsLeft"]-first_row["unavailableSeatsRight"]-first_row["unavailableSeatsLeft"]
            seats_available_second_row=4-second_row["takenSeatsLeft"]-second_row["takenSeatsLeft"]-second_row["unavailableSeatsRight"]-second_row["unavailableSeatsLeft"]
            if (numberOfPassengers<=seats_available_first_row and numberOfPassengers<=seats_available_second_row):
                if (seats_available_first_row<seats_available_second_row):
                    self._place_passengers_in_row(first_row,numberOfPassengers,passenger_or_group_id)
                else:
                    self._place_passengers_in_row(second_row,numberOfPassengers,passenger_or_group_id)
            elif (numberOfPassengers<=seats_available_first_row)
                self._place_passengers_in_row(first_row, numberOfPassengers, passenger_or_group_id)
            elif (numberOfPassengers<=seats_available_second_row):
                self._place_passengers_in_row(second_row, numberOfPassengers, passenger_or_group_id)

    def remove_passengers(self,passenger_or_group_id):
        for row in self.aircraft:
            if (row["passengerOrGroupIds"][passenger_or_group_id]):
                self._remove_passengers_in_row(row,passenger_or_group_id)

    def get_n_of_unavailable_seats(self):
        n=0
        for row in self.aircraft:
            n+=row["takenSeatsLeft"]+row["takenSeatsLeft"]+row["unavailableSeatsRight"]+row["unavailableSeatsLeft"]
        return n

    def get_n_of_avaiable_seats(self):
        return 40-self.get_n_of_unavailable_seats()