B"There is a tree consisting of n vertices. The vertices are numbered from 1 to n. Let's define the length of an interval [l, xe2 x80 x89r] as the value r xe2 x80 x89- xe2 x80 x89l xe2 x80 x89+ xe2 x80 x891. The score of a subtree of this tree is the maximum length of such an interval [l, xe2 x80 x89r] that, the vertices with numbers l, xe2 x80 x89l xe2 x80 x89+ xe2 x80 x891, xe2 x80 x89..., xe2 x80 x89r belong to the subtree. Considering all subtrees of the tree whose size is at most k, return the maximum score of the subtree. Note, that in this problem tree is not rooted, so a subtree -- is an arbitrary connected subgraph of the tree. There are two integers in the first line, n and k (1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89k xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89n xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89105). Each of the next n xe2 x80 x89- xe2 x80 x891 lines contains integers ai and bi (1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89ai, xe2 x80 x89bi xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89n, xe2 x80 x89ai xe2 x80 x89 xe2 x89 xa0 xe2 x80 x89bi). That means ai and bi are connected by a tree edge. It is guaranteed that the input represents a tree. Output should contain a single integer -- the maximum possible score. For the first case, there is some subtree whose size is at most 6, including 3 consecutive numbers of vertices. For example, the subtree that consists of {1, xe2 x80 x893, xe2 x80 x894, xe2 x80 x895, xe2 x80 x897, xe2 x80 x898} or of {1, xe2 x80 x894, xe2 x80 x896, xe2 x80 x897, xe2 x80 x898, xe2 x80 x8910} includes 3 consecutive numbers of vertices. But there is no subtree whose size is at most 6, which includes 4 or more consecutive numbers of vertices."...