You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule (8R,9S,13S,14S)-13-methyl-6-[(4-nitrophenyl)methoxyimino]-8,9,11,12,14,15,16,17-octahydro-7H-cyclopenta[a]phenanthrene-3,17-diol .
user
C25H28N2O5
assistant