You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named ethyl 8-ethyl-2-methylsulfanyl-5-oxo-6,7-dihydropyrido[2,3-d]pyrimidine-6-carboxylate by IUPAC nomenclature, provide its molecular formula.
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C13H17N3O3S
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