Instruct: Classify the given Amazon review as either positive or negative.
Query: Personal and Technical Account of Greatest Secret of WWII

The greatest secret of WWII is that the Allied Governments were able to read the German coded transmissions. This was often on a "Real Time" basis. The history books are being revised due to acknowledgement of this great technical feat.The book is a combination of personal account and technical review of the people intimately involved in the origins of the codebreaking. It is about the Polish mathematicians and students who first "cracked" the Enigma Code, and how they protected the secret, evolved with the changes for several years before the war started, and how they jump-started the British efforts on the eve of the German Invasion of Poland.Compelling reading, both from the personal and mathematical side. You do NOT need math to appreciate the impact of these unsung warriors.