You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-methylspiro[pyrrolidine-3,2'-tricyclo[9.4.0.03,8]pentadeca-1(15),3,5,7,11,13-hexaene]-2,5-dione The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H17NO2
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