You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 1-[2-[(3R)-5-(4-bromophenyl)-3-(4-fluorophenyl)-3,4-dihydropyrazol-2-yl]-2-oxoethyl]-4-ethylpiperazine-2,3-dione by IUPAC nomenclature, provide its molecular formula.
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C23H22BrFN4O3
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