You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(1R,3S)-N-[(1R,2R,4S)-7-cyano-7-azabicyclo[2.2.1]heptan-2-yl]-3-(2,5-dichlorophenyl)cyclopentane-1-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H21Cl2N3O
assistant