You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Name the molecular formula for the molecule established as (5S)-10,13-dimethyl-2,4,5,6,7,8,9,11,12,16-decahydro-1H-cyclopenta[a]phenanthrene-3,17-dione using the IUPAC nomenclature.
user
C19H26O2
assistant