You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule N-[2-[2-[(2-methoxyphenyl)methyl]-5-oxa-2-azaspiro[3.4]octan-8-yl]ethyl]pyrrolidine-1-carboxamide ?
user
C21H31N3O3
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