What in the world. In one of your past posts, specifically this one:

http://www.mathhelpforum.com/math-he...rs-154495.html

You clearly state that you know the congruence classes are -1, 0, and 1. And in this post, you're asking what the congruence classes are. This doesn't make any sense, what's going on?

By the way, the congruence classes are -1, 0, and 1, which you seemed to know earlier but not now.