You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule N'-(1,1a,6,6a-tetrahydrocyclopropa[a]inden-1-ylmethyl)-N-ethyl-2-oxa-7-azaspiro[4.4]nonane-7-carboximidamide;hydroiodide into molecular formula.
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C21H30IN3O
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