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 1-[2-(5-chloro-6-methylthieno[2,3-d]pyrimidin-4-yl)sulfanylacetyl]-3-ethylimidazolidin-4-one is given. What is its corresponding molecular formula?
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C14H15ClN4O2S2
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