You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-bromo-5-[1-(5-chlorothiophen-2-yl)ethylamino]-2-(2-methylpropyl)pyridazin-3-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C14H17BrClN3OS
assistant