You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(2-cyanoethyl)-N-(3,4-dimethylphenyl)-2-(2',5'-dioxospiro[6,7,8,9-tetrahydrobenzo[7]annulene-5,4'-imidazolidine]-1'-yl)acetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C26H28N4O3
assistant