You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[4-[(2,4-dioxo-1,3-diazaspiro[4.6]undecan-3-yl)methyl]-2-oxochromen-7-yl]acetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H23N3O5
assistant