You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[4-(4-pyridin-3-ylphenyl)-6-spiro[fluorene-9,14'-tetracyclo[13.4.0.02,7.08,13]nonadeca-1(19),2,4,6,8(13),9,11,15,17-nonaene]-11'-yl-1,3,5-triazin-2-yl]benzonitrile is the IUPAC name of a molecule. Please give its molecular formula.
user
C52H31N5
assistant