You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[2-(4-fluorophenyl)-6-methyl-5-oxo-4-phenylpyridazin-3-yl]-3,4,5-trimethoxybenzamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H24FN3O5
assistant