You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Translate the chemical IUPAC name 2-(3-bromophenyl)-5-[(2R)-2-(4-fluorophenyl)-2-hydroxyethyl]pyrazolo[1,5-a]pyrazin-4-one into its molecular formula.
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C20H15BrFN3O2
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