You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 1-(2-tert-butylsulfonylethyl)-2-methyl-3-spiro[3,4-dihydrochromene-2,1'-cyclopentane]-4-ylguanidine;hydroiodide into its molecular formula.
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C21H34IN3O3S
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