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 1-[4-(4-fluorophenyl)-7,7-dimethyl-2-propan-2-yl-5,6-dihydrocyclopenta[b]pyridin-3-yl]ethanone .
user
C21H24FNO
assistant