The best response to this question is: "yeah... I think we're done here?". The retards who think this is a good way to filter a good programmer from a bad programmer are idiotic enough to offer you a job because obviously you are exactly the kind of kick-ass person who can shock people awake and repair the defective nature of their company, the fact that working there would be like working at Initech from Office space.
The real source of the question is to sense your desperation levels. If you answer it the canned response way: "turning the negative into the positive". It's a sign across your forehead that says: "please....please.... I'm desperate! Please dominate me!".
Seriously. Just try it once. Laugh at them and excuse yourself, you'll fall off the chair in memorization when you see the job offer pop into your email inbox. I've done it.
It'll leave you with existential questions: wondering who the hell designed this idiotic physics engine we've found ourselves in. How can people survive making these calibre of poor decisions from day to day?