Second Largest Unique Number

You are given T test cases. For each test case, you are given a list of integers. Your task is to determine the second largest unique number in the list. If there are fewer than two distinct numbers, output None.

More formally, let \( U \) be the set of unique numbers from the list. If \(|U| < 2\), then the answer is None; otherwise, if the unique numbers sorted in descending order are \( u_1, u_2, \dots \), then the answer is \( u_2 \).

inputFormat

The input is read from standard input and has the following format:

T
N1
a1 a2 ... aN1
N2
b1 b2 ... bN2
... 
NT
c1 c2 ... cNT

Here, the first line contains a single integer T denoting the number of test cases. For each test case, the first line contains an integer N representing the number of elements, followed by a line with N space-separated integers.

outputFormat

For each test case, output a single line containing the second largest unique number if it exists, or None if it does not.

## sample

2
5
2 3 5 5 6
4
1 1 3 3

5
1

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