You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(8S)-2-phenylspiro[5,7-dihydropyrano[4,3-d]pyrimidine-8,3'-pyrrolidine]-1'-yl]propan-1-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H21N3O2
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