You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-hydroxy-6,7-dimethoxy-2-oxo-N-[(E)-pyridin-2-ylmethylideneamino]-1H-quinoline-3-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H16N4O5
assistant