You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-[1-[(E)-2-phenylethenyl]sulfonylazetidin-3-yl]-3-(thiophen-2-ylmethyl)-1,2,4-oxadiazole is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H17N3O3S2
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