You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule (7S,8R,9S,10R,13S,14S,17S)-7,10,13,17-tetramethyl-1,2,3,4,7,8,9,11,12,14,15,16-dodecahydrocyclopenta[a]phenanthrene-3,17-diol ?
user
C21H34O2
assistant