Can you give the molecular formula of the molecule ethyl 1-[[(3S,3aR,4aS,5R,8aR,9aR)-8a-methyl-2-oxospiro[3a,4,4a,6,7,8,9,9a-octahydro-3H-benzo[f][1]benzofuran-5,2'-oxirane]-3-yl]methyl]piperidin-1-ium-4-carboxylate ?