You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance (8S,9S,10R,13S,14S,16R,17S)-17-acetyl-10,13,16-trimethyl-2,8,9,12,14,15,16,17-octahydro-1H-cyclopenta[a]phenanthrene-3,11-dione .
user
C22H28O3
assistant