You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 1-(4-bromo-3-methylphenyl)-3-[(E)-[5-(5-chloro-2-methylphenyl)furan-2-yl]methylideneamino]urea by IUPAC nomenclature, provide its molecular formula.
user
C20H17BrClN3O2
assistant