You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-(3a-methyl-1,5-dioxo-2,3-dihydropyrrolo[1,2-a]quinazolin-4-yl)-N-[3-(3-methyl-1,2,4-oxadiazol-5-yl)propyl]butanamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H27N5O4
assistant