Definition: Generate a correct and concise answer for the question based on the words in the context.
Input: Context : Hans Lotter (17 November 1917 -- 21 November 2008) was a highly decorated Oberleutnant in the Luftwaffe during World War II, and a recipient of the Knight's Cross of the Iron Cross. 
Question : In what military branch did Hans Lotter serve?
Output:
Luftwaffe