You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (8R,9S,13S,14S,17S)-2-methoxy-13-methyl-6-(pyridin-4-ylmethoxyimino)-8,9,11,12,14,15,16,17-octahydro-7H-cyclopenta[a]phenanthrene-3,17-diol by IUPAC nomenclature, provide its molecular formula.
user
C25H30N2O4
assistant