You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[4-(4-ethylpiperazin-1-yl)phenyl]-2-oxo-3,4-dihydro-1H-quinoline-6-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H26N4O2
assistant