2 (2 pt). Now suppose that n ninjas are participating in the Chunin exam. Show that when all the fights are finished, we can always put these n ninjas in a queue, so that each ninja defeats the one who is standing right behind (i.e., the 1 st ninja beats the 2 nd ninja, the 2 nd ninja beats the 3 rd ninja..., the (n 1)th ninja beats the n th ninja )