QTREE4 - Query on a tree IV

给定一棵 $n$ 个点的带边权的树，点从 $1$ 到 $n$ 编号。每个点可能有两种颜色：黑或白。我们定义 $dist(a,b)$ 为点 $a$ 至点 $b$ 路径上的权值之和。 一开始所有的点都是白色的。 要求作以下操作： `C a` 将点 $a$ 的颜色反转。（黑变白，白变黑） `A` 询问 $dist(a,b)$ 的最大值。$a,b$ 点都必须为白色（$a$ 与 $b$ 可以相同），显然如果树上仍存在白点，查询得到的值一定是个非负数。 特别地，如果 `A` 操作时树上没有白点，输出 `They have disappeared.`。 对于 $100\%$ 的数据，$N \leq 100000$，$Q \leq 100000$，$-10^3 \leq c \leq 10^3$。

You are given a tree (an acyclic undirected connected graph) with $N$ nodes, and nodes numbered $1,2,3\ldots,N$. Each edge has an integer value assigned to it (note that the value can be negative). Each node has a color, white or black. We define $dist(a, b)$ as the sum of the value of the edges on the path from node $a$ to node $b$. All the nodes are white initially. We will ask you to perfrom some instructions of the following form: - `C a` : change the color of node $a$.(from black to white or from white to black) - `A` : ask for the maximum $dist(a, b)$, both of node a and node $b$ must be white ($a$ can be equal to $b$). Obviously, as long as there is a white node, the result will alway be non negative.

- In the first line there is an integer $N$. ($N \leq 100000$) - In the next $N-1$ lines, the $i$-th line describes the $i$-th edge: a line with three integers $a,b,c$ denotes an edge between $a, b$ of value $c$. ($-10^3 \leq c \leq 10^3$) - In the next line, there is an integer $Q$ denotes the number of instructions. ($Q \leq 100000$) - In the next $Q$ lines, each line contains an instruction `C a` or `A`.

For each `A` operation, write one integer representing its result. If there is no white node in the tree, you should write `They have disappeared.`.

3
1 2 1
1 3 1
7
A
C 1
A
C 2
A
C 3
A

2
2
0
They have disappeared.