You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
O-[[(8R,9S,13S,14S)-13-methyl-17-oxo-7,8,9,11,12,14,15,16-octahydro-6H-cyclopenta[a]phenanthren-3-yl]] carbamothioate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H23NO2S
assistant