You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 3-ethyl-1-methyl-2-[2-(2-methylsulfonylethoxy)ethyl]-1-(2-thiophen-2-ylethyl)guanidine by IUPAC nomenclature, provide its molecular formula.
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C15H27N3O3S2
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