You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule (8S,9S,10R,13S,14S)-17,17-difluoro-6,10,13-trimethyl-1,2,8,9,12,14,15,16-octahydrocyclopenta[a]phenanthrene-3,11-dione .
user
C20H24F2O2
assistant