You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[5-[(1R,11R)-17-(difluoromethoxy)-12-methylsulfonyl-2,9,12-triazapentacyclo[9.7.1.02,10.03,8.013,18]nonadeca-3(8),4,6,9,13(18),14,16-heptaen-5-yl]pyrimidin-2-yl]piperazin-2-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H23F2N7O4S
assistant