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CF1557A.Ezzat and Two Subsequences
Ezzat and Two Subsequences
Ezzat has an array of integers (maybe negative). He wants to split it into two non-empty subsequences and , such that every element from the array belongs to exactly one subsequence, and the value of is the maximum possible value, where is the average of the subsequence .
A sequence is a subsequence of a sequence if can be obtained from by deletion of several (possibly, zero or all) elements.
The average of a subsequence is the sum of the numbers of this subsequence divided by the size of the subsequence.
For example, the average of is , so .
Input
The first line contains a single integer ()— the number of test cases. Each test case consists of two lines.
The first line contains a single integer ().
The second line contains integers ().
It is guaranteed that the sum of over all test cases does not exceed .
Output
For each test case, print a single value — the maximum value that Ezzat can achieve.
Your answer is considered correct if its absolute or relative error does not exceed .
Formally, let your answer be , and the jury's answer be . Your answer is accepted if and only if .
Note
In the first test case, the array is . These are all the possible ways to split this array:
- , , so the value of .
- , , so the value of .
- , , so the value of .
Therefore, the maximum possible value .
In the second test case, the array is . These are all the possible ways to split this array:
- , , so the value of .
- , , so the value of .
Therefore, the maximum possible value .
Samples
4
3
3 1 2
3
-7 -6 -6
3
2 2 2
4
17 3 5 -3
4.500000000
-12.500000000
4.000000000
18.666666667
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