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-(3,7-dimethyl-2,6-dioxopurin-1-yl)-N-[4-(2-oxo-3,4-dihydro-1H-quinolin-6-yl)-1,3-thiazol-2-yl]acetamide into molecular formula.
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C21H19N7O4S
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