You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 3-(1,3-benzothiazol-2-yl)-1-[4-(4-methoxyphenyl)piperazin-1-yl]prop-2-en-1-one into molecular formula.
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C21H21N3O2S
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