I'm a law student and exams are coming right up. I need to stay awake for 20 hours to study and maintain my concentration, so I just wanna ask which energy drink has the most caffeine that I can buy? This will gonna help me a lot. Thanks.

You are taking a risk doing this.  Those energy drinks are wicked with side effects, headaches, jitters, potential heart attacks, vomiting, back chills and the list goes on. Take it easy with that stuff. How much are you going to remember with side effects like that ?