You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-(2-methylphenyl)-1-[4-[(2R)-oxolane-2-carbonyl]-1-oxa-4,9-diazaspiro[5.5]undecan-9-yl]ethanone is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H30N2O4
assistant