You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[4-(2-fluoroethoxy)-2-pyridin-3-yl-1-oxa-9-azaspiro[5.5]undecan-9-yl]-(3-methyl-4-propan-2-yloxyphenyl)methanone The above is the IUPAC name of a molecule. Write its molecular formula.
user
C27H35FN2O4
assistant