You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 2-(4-fluorophenoxy)-1-[3-(1-methylsulfonylpiperidin-2-yl)-6,8-dihydro-5H-[1,2,4]triazolo[4,3-a]pyrazin-7-yl]ethanone into molecular formula.
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C19H24FN5O4S
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