You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
calcium;6-[2-carboxy-6-(2-carboxylato-4,5,6-trihydroxyoxan-3-yl)oxy-4,5-dihydroxyoxan-3-yl]oxy-3,4,5-trihydroxyoxane-2-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H24CaO19
assistant