You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3S)-3-(3,5-dimethyl-1H-pyrazol-4-yl)-1-[4-(pyridin-3-ylamino)piperidin-1-yl]butan-1-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H27N5O
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