You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule 2-[6-(4-ethoxyphenyl)imidazo[2,1-b][1,3]thiazol-3-yl]-N-pyridin-4-ylacetamide into molecular formula.
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C20H18N4O2S
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