You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(1R,2R,6R,7R)-4-[(Z)-(3-bromo-4-hydroxy-5-methoxyphenyl)methylideneamino]-4-azatricyclo[5.2.2.02,6]undec-8-ene-3,5-dione is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H17BrN2O4
assistant