[{"from": "human", "value": "Generate a molecule based on this description. The molecule is a saturated long-chain fatty acid with a 20-carbon backbone. Arachidic acid is found naturally as a minor component of peanut oil."}, {"from": "gpt", "value": "[C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][=Branch1][C][=O][O]"}]