You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-(3-ethyl-1-methyl-5-sulfanylidene-4H-imidazo[4,5-c]pyrazol-6-yl)-1-methylpiperidin-2-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C13H19N5OS
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