You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (8S,9S,10S,13R,14S,17S)-17-ethyl-3,3-difluoro-10,13-dimethyl-1,2,4,5,6,7,8,9,11,12,14,15,16,17-tetradecahydrocyclopenta[a]phenanthrene into its molecular formula.
user
C21H34F2
assistant