You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-[(6-chloro-4H-1,3-benzodioxin-8-yl)methylsulfanyl]-2-(difluoromethyl)-4-(2-methylpropyl)-6-(trifluoromethyl)pyridine-3-carboxylic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H19ClF5NO4S
assistant