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 4-[(5S)-6-(4-ethoxy-3-fluorophenyl)-9,9-dimethyl-3,6-diazabicyclo[3.2.2]nonan-3-yl]butanenitrile .
user
C21H30FN3O
assistant