You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3S,5S,8S,9S,10S,13S,14S,17R)-17-acetyl-3-hydroxy-10,13-dimethyl-1,2,3,4,5,6,7,8,9,12,14,15,16,17-tetradecahydrocyclopenta[a]phenanthren-11-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H32O3
assistant