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CF2185C.Shifted MEX
Shifted MEX
You are given an array of integers . You are allowed to perform the following operation once.
- Select an integer (which may be negative), and for each value , set .
For example, if , and you perform the operation with , is now equal to .
Output the maximum possible value of after the operation is performed.
is defined as the smallest non-negative integer that is not present in the array. For example, is , and is .
Input
The first line of the input contains a single integer () — the number of test cases.
The first line of each test case contains a single integer () — the length of array .
The second line contains integers () — the array .
It is guaranteed that the sum of over all test cases does not exceed .
Output
For each test case, output the maximum possible value of after the operation has been performed.
Note
For the first test case, performing the operation with makes , and .
For the second test case, the is already , which is the highest possible, so we can perform the operation with , which will not change the array.
Samples
6
1
4
5
0 1 1 2 3
2
1 1
4
4 2 3 6
5
2 4 1 0 -1
6
-1 1 2 3 5 6
1
4
1
3
4
3
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