You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule 4-(3-bromophenyl)-N-(7-cyano-7-azabicyclo[2.2.1]heptan-2-yl)-2-methyl-4-oxobutanamide .
user
C18H20BrN3O2
assistant