You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 1-ethyl-2-[(5-ethylthiophen-2-yl)methyl]-3-[2-(4-sulfamoylphenyl)ethyl]guanidine;hydroiodide by IUPAC nomenclature, provide its molecular formula.
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C18H27IN4O2S2
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