You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule N-[[4-[4-[4-(N-(9,9-dimethylfluoren-2-yl)anilino)phenyl]phenyl]phenyl]methyl]-9,9-dimethyl-N-phenylfluoren-2-amine into molecular formula.
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C61H50N2
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