You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(1R,9S)-5-amino-11-(2-phenoxyacetyl)-7,11-diazatricyclo[7.3.1.02,7]trideca-2,4-dien-6-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H21N3O3
assistant