Given the task definition and input, reply with output. In this task, you are given books product reviews in English language. The goal is to classify the review as "POS" if the overall sentiment of the review is positive or as "NEG" if the overall sentiment of the review is negative.

An effort not reaching a good result . The book is written with the purpose to be an "up-to-date [source about] DC/DC converters for students and practicing professionals". It is a shame how this target is not reached. Since from the very begin, the introduction, you will face an answer: what is its usefulness? You'll hope that, going on reading, everything will be clearer, and, from a certain point of view, this is what you get: what you've seen in introduction is eventually explained so that it could be useful even to students. However the text neither is "practical" nor gives you the "in-depth-analysis" you were hoping since its title begins with "Advanced". Schematics are rarely useful to understand the following analysis and are often badly sketched/printed. Mathematical derivations are quite good but not enough to fulfill designers needs. Apart from this it is a good effort. In my opinion readers should have to wait the next edition, if there will be a next edition
NEG