You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 2-[1-(2-anilino-2-oxoethyl)-2,4-dioxo-4aH-thieno[3,2-d]pyrimidin-1-ium-3-yl]-N-(furan-2-ylmethyl)acetamide by IUPAC nomenclature, provide its molecular formula.
user
C21H19N4O5S+
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