You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 1'-(cyclobutanecarbonyl)-7-methoxy-1-oxospiro[2,3-dihydropyrido[3,4-b]indole-4,4'-piperidine]-9-carboxylic acid into its molecular formula.
user
C22H25N3O5
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