Instruct: Classify the given review into positive or negative sentiment.
Query: Lifesaver!

This cookbook has saved my sanity as well as my cooking skills! I recently moved from the Eastern seaboard to CO and everything I "knew" about baking went out the window. The change in altitude makes a huge difference in everything, but especially baked goods. This cookbook is a must for anyone wondering why their tried and true recipes aren't working at higher altitudes!