You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[(E)-2-(3-ethyl-5-methyl-1,3,4-thiadiazol-3-ium-2-yl)ethenyl]-3-methoxyphenol is the IUPAC name of a molecule. Please give its molecular formula.
user
C14H17N2O2S+
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