You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(8R,9S,10S,13R,14S,17R)-10,13-dimethyl-17-[(2R)-pentan-2-yl]-2,3,4,5,6,7,8,9,11,12,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthrene-12-carboxylic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C25H42O2
assistant