You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-[5-[(E)-2-[5-[(4-chloro-2-fluorophenyl)sulfamoyl]thiophen-2-yl]ethenyl]-3-methyl-1,2-oxazol-4-yl]acetamide by IUPAC nomenclature, provide its molecular formula.
user
C18H15ClFN3O4S2
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