You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
7-[2-(5-chloro-2-fluorophenyl)pyridin-3-yl]-2-methyl-1lambda6,2,4-benzothiadiazine 1,1-dioxide is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H13ClFN3O2S
assistant