You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3R,11S)-13-butyl-6-fluoro-3,11-dimethyl-10-oxa-2,13,17,18,21-pentazatetracyclo[13.5.2.04,9.018,22]docosa-1(21),4(9),5,7,15(22),16,19-heptaen-14-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H26FN5O2
assistant