So let's say always, when you always switch, let's think about how this might play out. What is your probability of winning? And before we even think about that, think about how you would win if you always switch. So if you pick wrong the first time, they're going to show you this, and so you should always switch. So if you pick door number 1, they're going to show you door number 3. You should switch. If you picked wrong door number 3, they're going to show you door number 1.