You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 2-[(4S)-4-(2,4-dichlorophenyl)-4-methyl-2,5-dioxoimidazolidin-1-yl]-N-[(2R)-pentan-2-yl]acetamide by IUPAC nomenclature, provide its molecular formula.
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C17H21Cl2N3O3
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