You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule 1'-(cyclopropylmethyl)-2-(2-phenylethyl)spiro[1,3,6,7,8,8a-hexahydropyrrolo[1,2-a]pyrazine-4,3'-azetidine]-7-ol into molecular formula.
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C21H31N3O
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