You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3R,4S)-4-ethenyl-4-methyl-1-(4-methylphenyl)sulfonyl-3-tri(propan-2-yl)silyloxyazetidin-2-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H35NO4SSi
assistant