The Line of Fire

Mr. Voldemort is a vicious criminal who intends to rob Azkaban. Azkaban is a country consisting of N cities which can be represented as a tree. But Dumbledore's Army (also known as the D.A.) were upto the task of stopping him. Azkaban had one highway which used to connect the cities lying at maximum distance from each other in the whole country i.e No other pair of cities were further apart from e