You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (8S,9S,10R,11R,13S,14S)-11-hydroxy-3-methoxy-10,13-dimethyl-1,2,7,8,9,11,12,14,15,16-decahydrocyclopenta[a]phenanthren-17-one into its molecular formula.
user
C20H28O3
assistant