You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[1-(2-bicyclo[4.1.0]heptanyl)-2-methyl-1-oxopropan-2-yl]-6-methyl-5-phenyl-2H-1,3-oxazin-4-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H27NO3
assistant