You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N,N-diethyl-3-[5-oxo-4-(thiophen-2-ylmethylidene)-1,3-oxazol-2-yl]benzenesulfonamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H18N2O4S2
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