Trevor is planning a 30-day trip to Africa, where he will visit three countries: first Benin,
then Ghana and then Togo. He wants to spend at least 2 and at most 12 days in Benin, at most 13 days
in Ghana, and at most 9 days in Togo. How many such itineraries are possible? (Assume that each day is
spent in just one country, and that she travels from one country to another at night.