You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 5-butan-2-yl-13-propan-2-yl-12-azatetracyclo[8.5.2.24,7.011,15]nonadeca-1(15),4,6,10,13,16,18-heptaene by IUPAC nomenclature, provide its molecular formula.
user
C25H31N
assistant