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 N-(1-naphthalen-2-ylethylidene)-N'-[1-(3-pyridin-3-ylphenyl)ethenyl]-9,9'-spirobi[fluorene]-2-carboximidamide .
user
C51H35N3
assistant