Please choose the correct ending to complete the given sentence: Health: [header] How to prevent seasonal affective disorder [title] Start making changes in early autumn. [step] If you've experienced sad in the past, take steps to prevent it before you start to experience symptoms. Begin preparing in late summer or early fall, before winter doldrums arrive.

Ending1: [title] Exercise for at least 30 minutes per day. [step] Exercise outdoors whenever possible, especially if it's sunny. Ending2: If you cannot find any shade or cover to work outside, organize your home as best as you can. Try not to startle your family and co-workers, which can trigger sad depression. Ending3: Whether you do this formally or not, clean your house and make things look good by putting on a sweater and the right hairstyle. Also fill out flyers and let people know by sending emails. Ending4: [substeps] It's a good idea to start making drastic changes in your lifestyle in early winter as early summer tends to be cooler. Try leaving the house and returning to school early so that you can have plenty of time to relax.

Answer format: ending1/ending2/ending3/ending4