456 has a tree of n nodes, each node is assigned with an integer number. Now 456 wants to select a subtree, such that the sum of all integers on the nodes of the subtree is maxmized. Can you help him? 

On the first line of the input is an integer T, and then T cases follows. Each case begins with a positive integer n(1 <= n <= 10^5), then n numbers Wi(-1000 <= Wi <= 1000),Wi for the number on the ith node. Then n - 1 lines follows, each line contains two numbers a, b(1 <= a, b <= n)indicate that there is a edge between node a and b.

For each test case, output one integer on a line, the maximized sum can be achieved by selecting a subtree.

3
1
5
2
5 -5
1 2
5
-2 -3 7 -1 4
1 2
2 3
3 4
2 5

5
5
8