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 (3S,8aS)-2-(2,5-dimethylthiophen-3-yl)sulfonyl-3-methyl-1,3,6,7,8,8a-hexahydropyrrolo[1,2-a]pyrazin-4-one into its molecular formula.
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C14H20N2O3S2
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