You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3S,11bS)-4,4-dideuterio-10-methoxy-3-(1,1,3,3,3-pentadeuterio-2-hydroxy-2-methylpropyl)-9-(trideuteriomethoxy)-3,6,7,11b-tetrahydro-1H-benzo[a]quinolizin-2-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H27NO4
assistant