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 3-[(4-chlorophenyl)methylsulfanyl]-7-(3-methoxyphenyl)-1,8a-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-8-one into molecular formula.
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C19H17ClN4O2S
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