You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named 7-acetyl-N-[1-(4-ethylphenyl)ethyl]-3-oxa-7,10-diazaspiro[5.6]dodecane-10-carboxamide is given. What is its corresponding molecular formula?
user
C22H33N3O3
assistant