class Parking:
    def __init__(self, minutes):
        self.minutes = minutes

    def calculate_fee(self):
        base_time = 30
        base_fee = 2000
        extra_fee_per_10 = 500

        if self.minutes <= base_time:
            return base_fee
        else:
            extra_minutes = self.minutes - base_time
            extra_units = (extra_minutes + 9) // 10
            return base_fee + extra_units * extra_fee_per_10

minutes = int(input("주차 시간(분) 입력: "))
parking = Parking(minutes)
print("주차 요금:", parking.calculate_fee(), "원")