B"You are given a tree consisting exactly of n vertices. Tree is a connected undirected graph with n-1 edges. Each vertex v of this tree has a value a_v assigned to it. Let dist(x, y) be the distance between the vertices x and y . The distance between the vertices is the number of edges on the simple path between them. Let's define the cost of the tree as the following value: firstly, let's fix some vertex of the tree. Let it be v . Then the cost of the tree is sum limits_{i = 1}^{n} dist(i, v) cdot a_i . Your task is to calculate the maximum possible cost of the tree if you can choose v arbitrarily. The first line contains one integer n , the number of vertices in the tree ( 1 <= n <= 2 cdot 10^5 ). The second line of the input contains n integers a_1, a_2, ... , a_n ( 1 <= a_i <= 2 cdot 10^5 ), where a_i is the value of the vertex i . Each of the next n - 1 lines describes an edge of the tree. Edge i is denoted by two integers u_i and v_i , the labels of vertices it connects ( 1 <= u_i, v_i <= n , u_i ne v_i ). It is guaranteed that the given edges form a tree. Print one integer -- the maximum possible cost of the tree if you can choose any vertex as v . Picture corresponding to the first example: You can choose the vertex 3 as a root, then the answer will be 2 cdot 9 + 1 cdot 4 + 0 cdot 1 + 3 cdot 7 + 3 cdot 10 + 4 cdot 1 + 4 cdot 6 + 4 cdot 5 = 18 + 4 + 0 + 21 + 30 + 4 + 24 + 20 = 121 . In the second example tree consists only of one vertex so the answer is always 0 . "...