You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name N-[3-[[N-ethyl-N'-[(5-ethylthiophen-2-yl)methyl]carbamimidoyl]amino]propyl]thiophene-2-carboxamide;hydroiodide into its molecular formula.
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C18H27IN4OS2
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