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 (3R,4'R)-6-chloro-5-fluoro-1',3',4'-triphenylspiro[1H-indole-3,5'-4H-pyrazole]-2-one is given. What is its corresponding molecular formula?
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C28H19ClFN3O
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