description: Vupsen and Pupsen were gifted an integer array. Since Vupsen doesn't like the number 0, he threw away all numbers equal to 0 from the array. As a result, he got an array a of length n.
  
  Pupsen, on the contrary, likes the number 0 and he got upset when he saw the array without zeroes. To cheer Pupsen up, Vupsen decided to come up with another array b of length n such that ∑_{i=1}^{n}a_i ⋅ b_i=0. Since Vupsen doesn't like number 0, the array b must not contain numbers equal to 0. Also, the numbers in that array must not be huge, so the sum of their absolute values cannot exceed 10^9. Please help Vupsen to find any such array b!
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 100) — the number of test cases. The next 2 ⋅ t lines contain the description of test cases. The description of each test case consists of two lines.
  
  The first line of each test case contains a single integer n (2 ≤ n ≤ 10^5) — the length of the array.
  
  The second line contains n integers a_1, a_2, …, a_n (-10^4 ≤ a_i ≤ 10^4, a_i ≠ 0) — the elements of the array a.
  
  It is guaranteed that the sum of n over all test cases does not exceed 2 ⋅ 10^5.
  
  Output
  
  For each test case print n integers b_1, b_2, …, b_n — elements of the array b (|b_1|+|b_2|+… +|b_n| ≤ 10^9, b_i ≠ 0, ∑_{i=1}^{n}a_i ⋅ b_i=0).
  
  It can be shown that the answer always exists.
  
  Example
  
  Input
  
  
  3
  2
  5 5
  5
  5 -2 10 -9 4
  7
  1 2 3 4 5 6 7
  
  
  Output
  
  
  1 -1
  -1 5 1 -1 -1
  -10 2 2 -3 5 -1 -1
  
  Note
  
  In the first test case, 5 ⋅ 1 + 5 ⋅ (-1)=5-5=0. You could also print 3 -3, for example, since 5 ⋅ 3 + 5 ⋅ (-3)=15-15=0
  
  In the second test case, 5 ⋅ (-1) + (-2) ⋅ 5 + 10 ⋅ 1 + (-9) ⋅ (-1) + 4 ⋅ (-1)=-5-10+10+9-4=0.
solution: 
  
  import java.io.*;
  import java.math.*;
  import java.util.*;
  
  
  // @author : Dinosparton 
  
  public class test {
  	 
  	   static class Pair{ 
  		   long x;
  		   long y;
  		   
  		   Pair(long x,long y){ 
  			   this.x = x;
  			   this.y = y;
  			   
  		   }
  	   }
  	 
  	   static class Sort implements Comparator<Pair>
  	   {
  
  	       @Override
  	       public int compare(Pair a, Pair b)
  	       {
  	           if(a.x!=b.x)
  	           {
  	               return (int)(a.x - b.x);
  	           }
  	           else
  	           {
  	               return (int)(a.y-b.y);
  	           }
  	       }
  	   }
  	   
  	   static class Compare { 
  		   
  		     void compare(Pair arr[], int n) 
  		    { 
  		        // Comparator to sort the pair according to second element 
  		        Arrays.sort(arr, new Comparator<Pair>() { 
  		            @Override public int compare(Pair p1, Pair p2) 
  		            { 
  		            	if(p1.x!=p2.x) {
  		                return (int)(p1.x - p2.x); 
  		            	}
  		            	else { 
  		            		return (int)(p1.y - p2.y);
  		            	}
  		            } 
  		        }); 
  		  
  //		        for (int i = 0; i < n; i++) { 
  //		            System.out.print(arr[i].x + " " + arr[i].y + " "); 
  //		        } 
  //		        System.out.println(); 
  		    } 
  		} 
  	 
  	   static class Scanner {
  	        BufferedReader br;
  	        StringTokenizer st;
  	 
  	        public Scanner()
  	        {
  	            br = new BufferedReader(
  	                new InputStreamReader(System.in));
  	        }
  	 
  	        String next()
  	        {
  	            while (st == null || !st.hasMoreElements()) {
  	                try {
  	                    st = new StringTokenizer(br.readLine());
  	                }
  	                catch (IOException e) {
  	                    e.printStackTrace();
  	                }
  	            }
  	            return st.nextToken();
  	        }
  	 
  	        int nextInt() { return Integer.parseInt(next()); }
  	 
  	        long nextLong() { return Long.parseLong(next()); }
  	 
  	        double nextDouble()
  	        {
  	            return Double.parseDouble(next());
  	        }
  	 
  	        String nextLine()
  	        {
  	            String str = "";
  	            try {
  	                str = br.readLine();
  	            }
  	            catch (IOException e) {
  	                e.printStackTrace();
  	            }
  	            return str;
  	        }
  	    }
  	
  	   	static int gcd(int a, int b)
  	   	{
  	   		if (a == 0)
  	   			return b;
  	   		return gcd(b % a, a);
  	   	}
  	   
  	   	static int lcm(int a, int b)
  	   	{
  	   		return (a / gcd(a, b)) * b;
  	   	}
  	   
  	 
  	   public static void main(String args[]) throws Exception { 
  		
  		   
  		   Scanner sc = new Scanner();
  		   StringBuilder res = new StringBuilder();
  		
  		   int tc = sc.nextInt();
  		  
  		   while(tc-->0) { 
  			
  			   int n = sc.nextInt();
  		        if (n%2!=0)
  		        {
  		            int a = sc.nextInt();
  		            int b = sc.nextInt();
  		            int c = sc.nextInt();
  		           
  		            if (b + c != 0)
  		                res.append( (b + c) + " " + -a + " " + -a + " ");
  		            else if (a + c != 0)
  		                res.append(-b + " " +(a + c) + " " + -b + " ");
  		            else
  		               res.append(-c + " " + -c + " " + (a + b )+ " ");
  		            n -= 3;
  		        }
  		        for (int i = 1; i <= n; i += 2)
  		        {
  		            int a = sc.nextInt();
  		            int b = sc.nextInt();
  		            
  		           res.append(-b+" "+a+" ");
  		        }
  		       res.append("\n");
  		   }
  		   System.out.println(res);
  	   }
  }  
  
  
  
  
  