title: BMW
context: BMW's origins can be traced back to three separate German companies: Rapp Motorenwerke, Bayerische Flugzeugwerke, and Automobilwerk Eisenach. The history of the name itself begins with Rapp Motorenwerke, an aircraft engine manufacturer. In April 1917, following the departure of the founder Karl Friedrich Rapp, the company was renamed Bayerische Motoren Werke (BMW).[3](p11) BMW's first product was the BMW IIIa aircraft engine. The IIIa engine was known for good fuel economy and high-altitude performance.[4] The resulting orders for IIIa engines from the German military caused rapid expansion for BMW.
question: What was the first BMW?
answers: BMW IIIa aircraft engine