You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (1S,2R,6S,9S,10S,11R,12S,14S,15S,16S,18S,20R,23R,24S)-10,12,14,16,20-pentahydroxy-6,10,23-trimethyl-4-azahexacyclo[12.11.0.02,11.04,9.015,24.018,23]pentacosan-17-one by IUPAC nomenclature, provide its molecular formula.
user
C27H43NO6
assistant