You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule (4Z)-5-(4-ethoxyphenyl)-4-[hydroxy-(4-methoxyphenyl)methylidene]-1-[2-(5-methoxy-1H-indol-3-yl)ethyl]pyrrolidine-2,3-dione .
user
C31H30N2O6
assistant