You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule 12-(1-methylbenzimidazol-2-yl)-10-(2-methylphenyl)-5-oxa-2,4,6,8,10-pentazatricyclo[7.3.0.03,7]dodeca-1,3,6,8,11-pentaen-11-amine .
user
C21H16N8O
assistant