You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[9,18,22-triacetyloxy-12-(furan-3-yl)-8,17,19,20-tetrahydroxy-1,11-dimethyl-4,14-dioxo-5,13-dioxahexacyclo[17.2.1.02,7.07,20.08,17.011,16]docosan-10-yl] acetate is the IUPAC name of a molecule. Please give its molecular formula.
user
C34H40O17
assistant