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 1'-(4-bromobenzoyl)-6-fluoro-1-methylspiro[3H-quinazoline-2,4'-piperidine]-4-one is given. What is its corresponding molecular formula?
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C20H19BrFN3O2
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