You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[2-[(4,5-dichlorothiophen-2-yl)sulfonylamino]phenyl]-1-methyl-3-oxo-2,1-benzothiazole-5-sulfonamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H13Cl2N3O5S4
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