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 (Z,4S)-4-(1,3-dioxoisoindol-2-yl)-3-hydroxy-2-(1-methylbenzimidazol-2-yl)pent-2-enenitrile into its molecular formula.
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C21H16N4O3
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