 They don't need air conditioning, and that would be more like Southern California. Let's see, on the question of how high, in writing this book, I did go and read a bunch of papers estimating the cost of construction as a function of the number of stories, and realizing, wow, there's a lot of disagreement here about exactly what the key breakpoints are. But a very common view is that 40 stories is crucial, and that up to there, basically from seven stories to 40, it's fairly constant cost per floor.