You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance [(1R,3S,5R)-6,6-dimethyl-2-methylidene-3-bicyclo[3.1.1]heptanyl] 3-methylimidazo[4,5-b]pyridine-6-carboxylate .
user
C18H21N3O2
assistant