You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule identified by (8R,9R,10R,11S,13S,14R,17R)-17-acetyl-17-hydroxy-11,13-dimethyl-1,2,6,7,8,9,10,11,12,14,15,16-dodecahydrocyclopenta[a]phenanthren-3-one ?
user
C21H30O3
assistant