You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(5'R,8'S,9'S,10'R,13'R,14'S,17'R)-4,4,4',4',10',13'-hexamethyl-17'-[(2R)-6-methylheptan-2-yl]-3-oxidospiro[1,3-oxazolidin-3-ium-2,3'-2,5,6,7,8,9,11,12,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthrene] is the IUPAC name of a molecule. Please give its molecular formula.
user
C33H59NO2
assistant