You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(4aS,4bS,10bR,12aS)-10-methoxy-1,1,4a-trimethyl-6,6-dioxo-3,4,4b,5,10b,11,12,12a-octahydro-2H-naphtho[1,2-c]thiochromen-8-ol is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H30O4S
assistant