This book is written for trainers and participants of mathematical
contests of all kinds up to the highest level of international
competitions, including the IMO and the Putnam Competition. It is also
written for high school teachers who are conducting a mathematics club
and are looking for ideas and problems for their club; for teachers who
want to pose "the problem of the week", "the problem of the month", "the
research problem of the year"; and for regular high school teachers who
are just looking for ideas to enrich their teaching by some interesting
nonroutine problems.