You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Translate the chemical IUPAC name 3-[2-(12-ethyl-13-oxo-4-oxa-8,12-diazadispiro[2.1.55.33]tridecan-8-yl)ethyl]benzonitrile;hydrochloride into its molecular formula.
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C21H28ClN3O2
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