You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named 7-carbazol-9-yl-4'-(2-nitrophenyl)-N,N-diphenylspiro[5,6,7,8-tetrahydrofluorene-9,9'-fluorene]-2-amine is given. What is its corresponding molecular formula?
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C55H39N3O2
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