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 ethyl (6S)-2-[(3,4-difluorobenzoyl)amino]-6-ethyl-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate into its molecular formula.
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C20H21F2NO3S
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