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What is the molecular formula of the compound with this IUPAC name 1-[6-(1,6-dimethyl-2-oxo-3H-pyridin-1-ium-4-yl)-5-(oxolan-3-ylmethoxy)-[1,3]thiazolo[5,4-b]pyridin-2-yl]-3-ethylurea ?
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C21H26N5O4S+
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