You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 2-(6,9b-dihydro-3aH-phenalen-2-yl)-4-phenyl-6-(4-spiro[fluorene-9,9'-xanthene]-3'-ylphenyl)-1,3,5-triazine by IUPAC nomenclature, provide its molecular formula.
user
C53H35N3O
assistant