You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[8-[(5-methylpyridin-3-yl)methoxy]-5-oxa-2-azaspiro[3.5]nonan-2-yl]-pyridazin-4-ylmethanone The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H22N4O3
assistant