You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(4R)-4-[(3S,5S,7R,8R,9S,10S,12S,13R,14S,17R)-7,12-dihydroxy-10,13-dimethyl-3-(octadecanoylamino)-2,3,4,5,6,7,8,9,11,12,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-17-yl]pentanoic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C42H75NO5
assistant