You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-[2-[(8S)-2-(3-cyanobenzoyl)-5-oxa-2-azaspiro[3.4]octan-8-yl]ethyl]-2-methoxyacetamide by IUPAC nomenclature, provide its molecular formula.
user
C19H23N3O4
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