You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(4S)-4-[(2R)-butan-2-yl]-N-(1-but-3-enylcyclohexanecarbonyl)-2,2-dimethyl-1,3-oxazolidine-3-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H36N2O3
assistant