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.util.*;
  
  public class tank {
  
      static final FastScanner fs = new FastScanner();
  
      static PrintWriter out = new PrintWriter(System.out);
  
      public static void main(String[] args) {
          int t = fs.nextInt();
          while(t-- > 0) run_case();
  
          out.close();
      }
  
      static void run_case() {
          int n = fs.nextInt();
          int[] a = fs.readArray(n);
          int[] b = new int[n];
  
          if(n % 2 != 0 && n > 3) {
              fn(a, b, 3, n - 1);
          } else if(n % 2 == 0) {
              fn(a, b, 0, n - 1);
          }
  
          if(n % 2 != 0) {
              l1:
              for (int i = 0; i < 3; i++) {
                  for (int j = 0; j < 3; j++) {
                      if(i != j) {
                          if((a[i] < 0 && a[j] < 0) || (a[i] > 0 && a[j] > 0)) {
                              il(a, b, i, j, (3 ^ i ^ j));
                              break l1;
                          }
                      }
                  }
              }
          }
  
          for(int i: b) out.print(i + " ");
          out.println();
      }
  
      static void il(int[] a, int[] b, int i1, int i2, int i3) {
          if(a[i2] == a[i1]) {
              b[i3] = -a[i2];
              if(a[i3] != (int) -1e4 && a[i3] != 1) {
                  b[i1] = 1;
                  b[i2] = a[i3] - 1;
              } else {
                  b[i1] = -1;
                  b[i2] = a[i3] + 1;
              }
  
              return;
          }
          b[i3] = a[i2] - a[i1];
          b[i1] = a[i3];
          b[i2] = -a[i3];
      }
  
      static void fn(int[] a, int[] b, int st, int en) {
          while(st < en) {
              b[st] = a[en];
              b[en] = -a[st];
              st++;
              en--;
          }
      }
  
      static class FastScanner {
          BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
          StringTokenizer st=new StringTokenizer("");
          String next() {
              while (!st.hasMoreTokens())
                  try {
                      st=new StringTokenizer(br.readLine());
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
              return st.nextToken();
          }
  
          String nextLine(){
              try {
                  return br.readLine();
              } catch (IOException e) {
                  e.printStackTrace();
              }
  
              return "";
          }
  
          int nextInt() {
              return Integer.parseInt(next());
          }
  
          int[] readArray(int n) {
              int[] a=new int[n];
              for (int i=0; i<n; i++) a[i]=nextInt();
              return a;
          }
  
          long nextLong() {
              return Long.parseLong(next());
          }
  
          double nextDouble() {
              return Double.parseDouble(next());
          }
      }
  }