Took about 10 minutes and, no, I didn't google the answer sheet. I guess if I was smarter (or less ethical, I'm not sure which, maybe both) I might have thought of that. From about 5 minutes to 8 minutes I was thinking that the answer was that there is no solution, but, being stubborn, I kept trying. I knew how the end had to play out and that helped me work the rest of it out.