def hotel_cost(nights):
    return 140 * nights

def plane_ride_cost(city):
    if city == "Charlotte":
        return 183
    elif city == "Tampa":
        return 220
    elif city == "Pittsburgh":
        return 222
    elif city == "Los Angeles":
        return 475

def rental_car_cost(days):
        cost = 40 * days
  if days>=7:
        cost -= 50
    elif days >=3:
        cost -= 20
    return cost