You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S,6R,9S,10R,14S)-9-(3-nitrophenyl)-8-azahexacyclo[13.7.1.02,6.08,23.010,14.016,21]tricosa-1(22),3,12,15(23),16,18,20-heptaene is the IUPAC name of a molecule. Please give its molecular formula.
user
C28H24N2O2
assistant