You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R,3R)-2-benzhydryl-N-(4-chlorophenyl)-N-methyl-1-azabicyclo[2.2.2]octan-3-amine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C27H29ClN2
assistant