You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[(8S,9S,10R,11S,13S,14R,17R)-17-(2-acetyloxyacetyl)-11-hydroxy-10,13-dimethyl-3-oxo-7,8,9,11,12,14,15,16-octahydro-6H-cyclopenta[a]phenanthren-17-yl] pentanoate is the IUPAC name of a molecule. Please give its molecular formula.
user
C28H38O7
assistant