You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-chloro-4-methyl-5-[2-[(2R,6S)-6-[4-(trifluoromethoxy)phenyl]oxan-2-yl]ethyl]pyridazine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H20ClF3N2O2
assistant