You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (8S,9R,10S,13S,14S)-2-ethoxy-3-hydroxy-10,13-dimethyl-2,3,4,5,6,7,8,9,12,14,15,16-dodecahydro-1H-cyclopenta[a]phenanthrene-11,17-dione into its molecular formula.
user
C21H32O4
assistant