[{"from": "human", "value": "Based on the given information, design a molecule that meets the desired specifications. The molecule is an oxopentanoic acid with the oxo group in the 5-position. It is an omega-oxo fatty acid, an aldehydic acid and an oxopentanoic acid. It is a conjugate acid of a 5-oxopentanoate."}, {"from": "gpt", "value": "[C][Branch1][Ring2][C][C][=O][C][C][=Branch1][C][=O][O]"}]