B"You are given n - 1 integers a_2, ... , a_n and a tree with n vertices rooted at vertex 1 . The leaves are all at the same distance d from the root. Recall that a tree is a connected undirected graph without cycles. The distance between two vertices is the number of edges on the simple path between them. All non-root vertices with degree 1 are leaves. If vertices s and f are connected by an edge and the distance of f from the root is greater than the distance of s from the root, then f is called a child of s . Initially, there are a red coin and a blue coin on the vertex 1 . Let r be the vertex where the red coin is and let b be the vertex where the blue coin is. You should make d moves. A move consists of three steps: Note that r and b can be equal at any time, and there is no number written on the root. After each move, you gain |a_r - a_b| points. What's the maximum number of points you can gain after d moves? The first line contains a single integer t ( 1 <= t <= 10^4 ) -- the number of test cases. The first line of each test case contains a single integer n ( 2 <= q n <= q 2 cdot 10^5 ) -- the number of vertices in the tree. The second line of each test case contains n-1 integers v_2, v_3, ... , v_n ( 1 <= q v_i <= q n , v_i neq i ) -- the i -th of them indicates that there is an edge between vertices i and v_i . It is guaranteed, that these edges form a tree. The third line of each test case contains n-1 integers a_2, ... , a_n ( 1 <= q a_i <= q 10^9 ) -- the numbers written on the vertices. It is guaranteed that the sum of n for all test cases does not exceed 2 cdot 10^5 . For each test case, print a single integer: the maximum number of points you can gain after d moves. In the first test case, an optimal solution is to: The tot"...