This is program that allows user to see how much they are going to spend or have to spend in, to take a vacation. At first I define a function called hotel_cost with one argument nights as input. Then I defined a function called plane_ride_cost that takes a string, city, as input and the function  return a different price depending on the location of the city. Then I defined another function called rental_car_cost with an argument called days. At the last I defined a function called trip_cost that takes three arguments, city,days and spending_money. Those function and inputs all summed up to the total cost of the trip and how much the user have to have for the vacation.