You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[2-(3-benzylimidazo[4,5-b]pyridin-2-yl)ethyl]-3-(4-bromo-2-fluorophenyl)urea The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H19BrFN5O
assistant