You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[9-[4,6-di(phenanthren-9-yl)pyrimidin-2-yl]carbazol-3-yl]-9-phenanthren-9-ylcarbazole is the IUPAC name of a molecule. Please give its molecular formula.
user
C70H42N4
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