You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(9R)-9-amino-7-[(2R,4S,5S)-4,5-dihydroxyoxan-2-yl]oxy-6,11-dihydroxy-9-(1-hydroxyethyl)-8,10-dihydro-7H-tetracene-5,12-dione is the IUPAC name of a molecule. Please give its molecular formula.
user
C25H27NO9
assistant