You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(3S,8R,9S,10R,13S,14S,17S)-3,17-dihydroxy-10,13-dimethyl-1,2,3,4,7,8,9,11,12,14,15,16-dodecahydrocyclopenta[a]phenanthren-17-yl]-5-methylhexan-2-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H42O3
assistant