Definition: Generate a question which can yield the answer mentioned in the input. Generated question must be answered by the answer provided in input, without using any extra knowledge.
Input: Context : F 13 Norrkoping, Bravalla Flygflottilj, Bravalla Air Force Wing, or simply ''F 13'', is a former Flygvapnet - Swedish Air Force - wing with the main base located near Norrkoping in south-eastern Sweden.
Answer : Swedish Air Force
Output:
What military branch did F 13 Norrkoping belong to?