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 ethyl 3-[(4-methoxycarbonyl-5-methylfuran-2-yl)methyl]-6-methyl-4-oxofuro[2,3-d]pyrimidine-5-carboxylate into molecular formula.
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C18H18N2O7
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