You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 4-[3-(2,6-dichlorophenyl)oxiran-2-yl]-1,2lambda6,3-benzoxathiazine 2,2-dioxide by IUPAC nomenclature, provide its molecular formula.
user
C15H9Cl2NO4S
assistant