You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R,8R,9S,10S,13S,14S,17R)-17-hydroxy-2,13-dimethyl-2,6,7,8,9,10,11,12,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-3-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H28O2
assistant