You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 2-(2,3-dimethoxyphenyl)-N-(6-ethyl-1,3-benzothiazol-2-yl)-1,3-thiazole-4-carboxamide into molecular formula.
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C21H19N3O3S2
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