You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2,4,8,10,17-pentazatetracyclo[8.7.0.03,8.011,16]heptadeca-1(17),2,4,6,11,13,15-heptaen-9-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C12H7N5O
assistant