Rules are straightforward. You need to choose a correct answer and you only have 5 seconds to respond. If you run out of time — you will lose. Incorrect choice will lead you to losing as well. In case of a correct answer your score will rise and a next question will follow. The faster you answer, the more points you get. More precisely, you will add up N×T points to your final score, where N is the number of vertices and T is the remaining time. As you move forward, the number of vertices in a graph steadily increases.