You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Name the molecular formula for the molecule established as 1-ethyl-4-fluoro-3-[(1R)-1-(3-fluorophenyl)-3-(methylamino)propyl]benzimidazol-2-one using the IUPAC nomenclature.
user
C19H21F2N3O
assistant