You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance (4R)-2-amino-4-(2-methoxyphenyl)-7,7-dimethyl-5-oxo-6,8-dihydro-4H-chromene-3-carbonitrile .
user
C19H20N2O3
assistant