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Tree and Level
Easy Accuracy: 69.75% Submissions: 367 Points: 2

Given a tree with N nodes rooted at 1. Each node labeled with a value arr[i]. The task is to find the absolute difference between the sum of values of nodes at even level and odd level

Note: All the nodes are numbered from 1 to N.

Input:
1. The first line of the input contains a single integer T denoting the number of test cases. The description of T test cases follows.
2. The first line of each test case contains a single integer N.
3. The next line contains N space-separated positive integers represents the node value.
4. Next N-1 lines contain two space-separated integers u and v, represents an edge in between them

Output: For each test case, print the answer

Constraints:
1. 1 <= T <= 5

2. 1 <= N <= 105
3. 1 <= arr[i] <= 105

Example:
Input:

2
4
1 2 3 4
1 2
3 4

4 1
5
1 2 1 2 1
1 2
2 3
3 4
4 5

Output:
2
1

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