You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[8-(2-methylbutan-2-yl)-2,4-dioxo-1,3-diazaspiro[4.5]decan-3-yl]-N-[2-(3-methylphenyl)-2-morpholin-4-ylethyl]acetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C28H42N4O4
assistant