I'm reading this book now. I like it because it's rigorous and interesting but I have too much difficulty solving the exercises. What's worse, Zorich didn't give the answers. Where can I find the answers? I mean is there a book or something that gives the answers or even just some hints to the exercises? If there's not, then how should I use this book? Is it worth reading if the exercises are skipped? By the way, my English is not good, if you can't understand my questions, just tell me and I'll try my best to explain.