You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the compound with this IUPAC name 3-(3-chloro-4-fluorophenyl)-1-(2-hydroxyethyl)-1-[(1S)-1-(1-oxo-2H-isoquinolin-4-yl)ethyl]urea ?
user
C20H19ClFN3O3
assistant