You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (1-ethylpyrazol-3-yl)-(4-methoxy-1-oxa-9-azaspiro[5.5]undecan-9-yl)methanone by IUPAC nomenclature, provide its molecular formula.
user
C16H25N3O3
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