You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule (1R,5S)-7-(4-bromophenyl)-6-[(4-fluorophenyl)methyl]-3-(2,2,2-trifluoroethyl)-3,6-diazabicyclo[3.1.1]heptane ?
user
C20H19BrF4N2
assistant