You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named 2-(3-methoxyphenoxy)-1-[4-(6-methylsulfanyl-1,3-benzothiazol-2-yl)piperazin-1-yl]ethanone is given. What is its corresponding molecular formula?
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C21H23N3O3S2
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