The book can be used in 'at least three ways. One can teach a onesemester course from it, choosing the most general topics. One can alson use the book for a two-semester course, teaching most of the text and exploring the supplementary material that is given in form of exercises.If one has already taught a one-semester course using a general Combi-natorics textbook and wants to follow up with a second semester that focuses on enumeration, one may use the last six chapters of this book.The book is also useful for teaching an introductory course for graduate students who do not have solid background in Combinatorics.