You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-(4-nitro-1,3-dioxoisoindol-2-yl)-N-(2-oxo-3,4-dihydro-1H-quinolin-6-yl)propanamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H16N4O6
assistant