You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
7-[4-(1,3-benzoxazol-2-yl)piperidine-1-carbonyl]-4-ethyl-1H-quinoxaline-2,3-dione is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H22N4O4
assistant