You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule N-[1-butyl-6-(1,5-dimethyl-6-oxo-2,3-dihydropyridin-3-yl)-3-(trifluoromethyl)indazol-4-yl]methanesulfonamide into molecular formula.
user
C20H25F3N4O3S
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