You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[1-methylsulfonyl-3-[3-[7-(2-oxo-1H-pyridin-4-yl)-1,6-naphthyridin-5-yl]pyrazol-1-yl]azetidin-3-yl]acetonitrile is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H19N7O3S
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