[{"from": "human", "value": "Synthesize a molecule that matches the given characteristics. The molecule is an octadecatrienoic acid."}, {"from": "gpt", "value": "[C][Branch1][#C][C][C][C][/C][=C][/C][=C][/C][=C][/C][C][C][C][O][C][C][C][C][=Branch1][C][=O][O]"}]