You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
trimethyl-[(Z)-2-[(2R,6S,9R)-7-(4-methylphenyl)sulfonyl-7-azatricyclo[4.3.0.02,9]nonan-9-yl]ethenyl]silane is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H29NO2SSi
assistant