Please choose the correct ending to complete the given sentence: Food and Entertaining: [header] How to stay up for three days straight [title] Extend your sleep slightly. [step] You'll want to bank a little bit of sleep beforehand, so don't be afraid to go to bed a little earlier or sleep in a bit in the days leading up to your time up. [title] Avoid caffeine.

Ending1: [step] Coffee is, extremely, environmentally disadvantageous and alcohol only contributes to tiredness and depression. While avoiding caffeine reduces energy, it also makes your body and mind feel sluggish and slows down the rate at which you wake up. Ending2: [step] You'll be taking in plenty of caffeine as the days go by. If you use too much in the days leading up to your time, you'll build up a tolerance. Ending3: [step] Caffeine has been shown to alter brain chemistry in some people, which can exacerbate sleep problems. When the news comes in about how your body reacts to caffeine, just don't drink anything too heavy in your sleep. Ending4: [step] Caffeine is a major cause of jet lag, but you should strive to limit the caffeine while traveling with jet lag. Caffeine can cause a toll on your overall day-to-day sleepiness, which in turn can make jet lag worse.

Answer format: ending1/ending2/ending3/ending4