You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule N-[(4-hydroxypyrrolidin-3-yl)methyl]-6-methyl-4-oxo-1-[2-(trifluoromethyl)phenyl]pyridazine-3-carboxamide;hydrochloride into molecular formula.
user
C18H20ClF3N4O3
assistant