description: Ezzat has an array of n integers (maybe negative). He wants to split it into two non-empty subsequences a and b, such that every element from the array belongs to exactly one subsequence, and the value of f(a) + f(b) is the maximum possible value, where f(x) is the average of the subsequence x. 
  
  A sequence x is a subsequence of a sequence y if x can be obtained from y 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 [1,5,6] is (1+5+6)/3 = 12/3 = 4, so f([1,5,6]) = 4.
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 10^3)— the number of test cases. Each test case consists of two lines.
  
  The first line contains a single integer n (2 ≤ n ≤ 10^5).
  
  The second line contains n integers a_1, a_2, …, a_n (-10^9 ≤ a_i ≤ 10^9).
  
  It is guaranteed that the sum of n over all test cases does not exceed 3⋅10^5.
  
  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 10^{-6}.
  
  Formally, let your answer be a, and the jury's answer be b. Your answer is accepted if and only if \frac{|a - b|}{max{(1, |b|)}} ≤ 10^{-6}.
  
  Example
  
  Input
  
  
  4
  3
  3 1 2
  3
  -7 -6 -6
  3
  2 2 2
  4
  17 3 5 -3
  
  
  Output
  
  
  4.500000000
  -12.500000000
  4.000000000
  18.666666667
  
  Note
  
  In the first test case, the array is [3, 1, 2]. These are all the possible ways to split this array: 
  
    * a = [3], b = [1,2], so the value of f(a) + f(b) = 3 + 1.5 = 4.5. 
    * a = [3,1], b = [2], so the value of f(a) + f(b) = 2 + 2 = 4. 
    * a = [3,2], b = [1], so the value of f(a) + f(b) = 2.5 + 1 = 3.5. 
  
  Therefore, the maximum possible value 4.5.
  
  In the second test case, the array is [-7, -6, -6]. These are all the possible ways to split this array: 
  
    * a = [-7], b = [-6,-6], so the value of f(a) + f(b) = (-7) + (-6) = -13. 
    * a = [-7,-6], b = [-6], so the value of f(a) + f(b) = (-6.5) + (-6) = -12.5. 
  
  Therefore, the maximum possible value -12.5.
solution: 
  import java.util.Scanner;
  
  public class Ezzat_and_Two_Subsequences {
  	public static void main (String args[]) {
  		Scanner in = new Scanner (System.in);
  		int cases = in.nextInt();
  		in.nextLine();
  		int numbers;
  		String bruh = "";
  		
  		double avg= 0.0;
  		for (int counter = 0; counter < cases; counter++) {
  			int maximum ;
  			numbers = in.nextInt();
  			in.nextLine();
  			bruh = in.nextLine();
  			String[] transfer = new String [numbers];
  			transfer = bruh.split(" ");
  			int [] cringe = new int [numbers];
  			for (int transfercounter = 0; transfercounter<numbers;transfercounter++) {
  				cringe [transfercounter] = Integer.parseInt (transfer[transfercounter]);
  			}
  			//find largest number
  			maximum = cringe[0];
  			for (int maxc = 0; maxc<numbers;maxc++) {
  				if(cringe[maxc]>maximum) {
  					maximum = cringe[maxc];
  				}
  			}
  			//find average of rest of the set
  			for (int avgc =0; avgc<numbers;avgc++) {
  				avg = avg + (double)(cringe[avgc]);
  			}
  			avg = avg - (double)maximum;
  			avg = avg/(double)(numbers-1);
  			System.out.println(((double)maximum+avg));
  			maximum = 0;
  			avg = 0.0;
  		}
  	}
  }