You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named 3-(4-ethoxyphenyl)-2-methylsulfanyl-6,7-dihydrothieno[3,2-d]pyrimidin-4-one is given. What is its corresponding molecular formula?
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C15H16N2O2S2
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