You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-cyclopropyl-N-[9-(3-fluorobenzoyl)-1-oxa-9-azaspiro[5.5]undecan-4-yl]ethanesulfonamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H29FN2O4S
assistant