print(trip_cost("Los Angeles", 5, 600))
 trip_cost("Los Angeles", 5, 600)
  rental_car_cost(days) + hotel_cost(days - 1) + plane_ride_cost(city) + spending_money
   rental_car_cost(days)
    days
    5
   rental_car_cost(5)
    ...
   180
  180 + hotel_cost(days - 1) + plane_ride_cost(city) + spending_money
   hotel_cost(days - 1)
    days - 1
     days
     5
    4
   hotel_cost(4)
    ...
   560
  180 + 560 + plane_ride_cost(city) + spending_money
  740 + plane_ride_cost(city) + spending_money
   plane_ride_cost(city)
    city
    "Los Angeles"
   plane_ride_cost("Los Angeles")
    ...
   475
  740 + 475 + spending_money
  1215 + spending_money
   spending_money
   600
  1215 + 600
  1815
 1815