You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(6R,9S)-9-(2-chlorophenyl)-6-(4-hydroxy-3-methoxy-5-nitrophenyl)-5,6,8,9,10,11-hexahydrobenzo[b][1,4]benzodiazepin-7-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H22ClN3O5
assistant