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 4-[(4S)-4-benzyl-5-oxo-2-sulfanylideneimidazolidin-1-yl]-1,5-dimethyl-2-phenylpyrazol-3-one into its molecular formula.
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C21H20N4O2S
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