You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R,3S)-2-amino-3-hydroxy-1-spiro[4,9-dihydro-3H-pyrano[3,4-b]indole-1,4'-piperidine]-1'-ylbutan-1-one;hydrochloride is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H26ClN3O3
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