You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4'-(15,15-dimethyl-19-phenyl-11,19-diazaheptacyclo[14.11.0.02,14.04,12.05,10.018,26.020,25]heptacosa-1(16),2(14),3,5,7,9,12,17,20,22,24,26-dodecaen-11-yl)spiro[8,9-dihydroindolo[1,2-a]benzimidazole-11,9'-fluorene] is the IUPAC name of a molecule. Please give its molecular formula.
user
C59H40N4
assistant