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: // Generated by Code Flattener.
  // https://plugins.jetbrains.com/plugin/9979-idea-code-flattener
  
  import java.io.*;
  import java.util.StringTokenizer;
  
  public class Main {
      public static void main(String[] args) {
          Solution solution = new ASolution();
          boolean local = System.getProperty("ONLINE_JUDGE") == null && !solution.isInteractive();
          String input = local ? "input.txt" : null;
          solution.in = new MyScanner(input);
          solution.out = MyWriter.of(null);
          solution.bm = new Benchmark();
          solution.al = new Algorithm();
          solution.run();
          solution.close();
      }
  
      private abstract static class Solution {
          public MyScanner in;
          public MyWriter out;
          public Benchmark bm;
          public Algorithm al;
  
          public void init() {
          }
  
          public abstract void solve();
  
          protected boolean isMultiTest() {
              return true;
          }
  
          public void run() {
              init();
              if (isMultiTest()) {
                  int t = in.nextInt();
                  for (int i = 0; i < t; i++) {
                      solve();
                  }
              } else {
                  solve();
              }
          }
  
          public void close() {
              out.close();
          }
  
          public boolean isInteractive() {
              return false;
          }
      }
  
      private static class ASolution extends Solution {
          int get(int x, int y, boolean plus) {
              if (y < 0 == plus == x < 0) return x;
              else return -x;
          }
  
          public void solve() {
              int n = in.nextInt();
              int[] a = in.nextInts(n);
              int[] b = new int[n];
              for (int i = 0; i < (n % 2 == 0 ? n : n - 3); i += 2) {
                  b[i] = get(a[i + 1], a[i], true);
                  b[i + 1] = get(a[i], a[i + 1], false);
              }
              if (n % 2 == 1) {
                  int tmp = Math.abs(a[n - 3]) - Math.abs(a[n - 2]);
                  if (tmp != 0) {
                      b[n - 3] = get(a[n - 1], a[n - 3], true);
                      b[n - 2] = get(a[n - 1], a[n - 2], false);
                      b[n - 1] = get(tmp, a[n - 1], tmp < 0);
                  } else {
                      int tmp2 = Math.abs(a[n - 1]);
                      int bn3;
                      int bn2;
                      if (tmp2 != 1) {
                          bn3 = tmp2 - 1;
                          bn2 = 1;
                      } else {
                          bn3 = 2;
                          bn2 = -1;
                      }
                      b[n - 3] = get(bn3, a[n - 3], true);
                      b[n - 2] = get(bn2, a[n - 2], bn2 > 0);
                      b[n - 1] = get(a[n - 3], a[n - 1], false);
  
                  }
              }
              for (int el : b) {
                  out.print(el + " ");
              }
              out.println();
          }
      }
  
      private static class MyScanner {
          private final BufferedReader br;
          private StringTokenizer st;
  
          public MyScanner(String fileName) {
              if (fileName != null) {
                  try {
                      File file = new File(getClass().getClassLoader().getResource(fileName).getFile());
                      br = new BufferedReader(new FileReader(file));
                  } catch (FileNotFoundException e) {
                      throw new RuntimeException(e);
                  }
              } else {
                  br = new BufferedReader(new InputStreamReader(System.in));
              }
          }
  
          public String next() {
              while (st == null || !st.hasMoreElements()) {
                  st = new StringTokenizer(nextLine());
              }
              return st.nextToken();
          }
  
          public int nextInt() {
              return Integer.parseInt(next());
          }
  
          public int[] nextInts(int n) {
              int[] arr = new int[n];
              for (int i = 0; i < n; i++) {
                  arr[i] = nextInt();
              }
              return arr;
          }
  
          public String nextLine() {
              try {
                  String line = br.readLine();
                  if (line == null) {
                      throw new RuntimeException("empty line");
                  }
                  st = null;
                  return line;
              } catch (IOException e) {
                  throw new RuntimeException(e);
              }
          }
      }
  
      private static class Benchmark {
      }
  
      private static class Algorithm {
      }
  
      private static class MyWriter extends PrintWriter {
          public static MyWriter of(String fileName) {
              if (fileName != null) {
                  try {
                      return new MyWriter(new FileWriter(fileName));
                  } catch (IOException e) {
                      throw new RuntimeException(e);
                  }
              } else {
                  return new MyWriter(new BufferedOutputStream(System.out));
              }
          }
  
          public MyWriter(Writer writer) {
              super(writer);
          }
  
          public MyWriter(OutputStream out) {
              super(out);
          }
      }
  }