You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (5S,8S,9S,10S,13S,14S)-10,13-dimethyl-2,3,4,5,7,8,9,12,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthrene-6,11-dione into its molecular formula.
user
C19H28O2
assistant