You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[(2S,3R,4S,6R)-2-[4-chloro-3-[(2-cyano-3,4-dihydro-2H-1,4-benzoxazin-6-yl)methyl]phenyl]-6-ethyl-4,5-dimethyloxan-3-yl] acetate is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H31ClN2O4
assistant