You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
methyl (3aR,4R,6S,7aS)-3-acetyl-6-[(2S,3R,4S,5S,6R)-2-[(2R,3R,4S,5R,6R)-6-[5-[benzyl(phenylmethoxycarbonyl)amino]pentoxy]-4,5-bis(phenylmethoxy)-2-(phenylmethoxymethyl)oxan-3-yl]oxy-5-hydroxy-3-phenylmethoxy-6-(phenylmethoxymethyl)oxan-4-yl]oxy-2-oxo-4-[(1S,2R)-1,2,3-triacetyloxypropyl]-3a,4,7,7a-tetrahydropyrano[3,4-d][1,3]oxazole-6-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C86H98N2O25
assistant