You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[4-(1,2,3,4,4a,5,6,7,8,8a-decahydronaphthalen-2-yl)-4-oxobutyl]-4-hydroxyindene-1,3-dione is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H28O4
assistant