You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 1-(4-fluorophenyl)-4-oxo-N-propan-2-yl-N-pyridin-3-ylpyridazine-3-carboxamide by IUPAC nomenclature, provide its molecular formula.
user
C19H17FN4O2
assistant