[{"from": "human", "value": "Synthesize a molecule that matches the given characteristics. The molecule is an amino disaccharide comprised of N-acetyl-alpha-D-galactosamine having an N-acetyl-D-galactosaminyl residue attached at the 3-position via a beta-linkage. It has a role as an epitope."}, {"from": "gpt", "value": "[C][C][=Branch1][C][=O][N][C@@H1][C@H1][Branch2][Ring2][=Branch2][C@H1][Branch2][Ring2][Ring2][C@H1][Branch2][Ring1][=C][O][C@H1][Ring1][=Branch1][O][C@@H1][C@H1][Branch1][#C][C@H1][Branch1][O][O][C@@H1][Branch1][Branch1][C@@H1][Ring1][=Branch1][O][C][O][O][N][C][=Branch1][C][=O][C][C][O][O][O]"}]