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.OutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.PrintWriter;
  import java.util.Objects;
  import java.util.InputMismatchException;
  import java.io.IOException;
  import java.util.Comparator;
  import java.util.ArrayList;
  import java.io.InputStream;
  
  /**
   * Built using CHelper plug-in
   * Actual solution is at the top
   */
  public class Main {
      public static void main(String[] args) {
          InputStream inputStream = System.in;
          OutputStream outputStream = System.out;
          InputReader in = new InputReader(inputStream);
          PrintWriter out = new PrintWriter(outputStream);
          DVupsenPupsenI0 solver = new DVupsenPupsenI0();
          int testCount = Integer.parseInt(in.next());
          for (int i = 1; i <= testCount; i++)
              solver.solve(i, in, out);
          out.close();
      }
  
      static class DVupsenPupsenI0 {
          public void solve(int testNumber, InputReader in, PrintWriter out) {
              int n = in.nextInt();
              ArrayList<Pair<Integer, Integer>> a = new ArrayList<>();
              int[] b = new int[n];
              for (int i = 0; i < n; i++) {
                  int val = in.nextInt();
                  b[i] = val;
                  a.add(Pair.of(i, val));
              }
              a.sort(Comparator.comparingInt(x -> x.sc));
              int[] ans = new int[n];
  
              if (n % 2 == 1) {
                  boolean found = false;
                  int j = -1;
                  for (int i = 2; i < n; i++) {
                      if (a.get(i - 2).sc == a.get(i).sc) {
                          found = true;
                          ans[a.get(i - 2).fs] = 2;
                          ans[a.get(i - 1).fs] = -1;
                          ans[a.get(i).fs] = -1;
                          j = i;
                          break;
                      }
                  }
                  if (found) {
                      a.remove(j);
                      a.remove(j - 1);
                      a.remove(j - 2);
                  } else {
                      Pair<Integer, Integer> j1 = a.get(n - 1);
                      Pair<Integer, Integer> j2 = a.get(n - 2);
                      Pair<Integer, Integer> j3 = a.get(n - 3);
                      int s1 = j1.sc + j2.sc;
                      if (s1 == 0) {
                          Pair<Integer, Integer> z = j1;
                          j1 = j3;
                          j3 = z;
                          s1 = j1.sc + j2.sc;
                      }
                      int s2 = j3.sc;
  
                      ans[j1.fs] = -s2;
                      ans[j2.fs] = -s2;
                      ans[j3.fs] = s1;
                      a.remove(a.size() - 1);
                      a.remove(a.size() - 1);
                      a.remove(a.size() - 1);
                  }
              }
              for (int i = 1; i < a.size(); i += 2) {
                  Pair<Integer, Integer> j1 = a.get(i - 1);
                  Pair<Integer, Integer> j2 = a.get(i);
                  ans[j1.fs] += -j2.sc;
                  ans[j2.fs] += j1.sc;
              }
  
              int ssum = 0;
  
  
              for (int i = 0; i < n; i++) {
                  ssum += ans[i] * b[i];
                  out.print(ans[i] + " ");
              }
              out.println();
  //        out.println(ssum);
  
  
          }
  
      }
  
      static class Pair<T, K> {
          T fs;
          K sc;
  
          public Pair(T fs, K sc) {
              this.fs = fs;
              this.sc = sc;
          }
  
          public static <T, K> Pair<T, K> of(T fs, K sc) {
              return new Pair<>(fs, sc);
          }
  
          public boolean equals(Object o) {
              if (this == o) {
                  return true;
              }
              if (o == null || getClass() != o.getClass()) {
                  return false;
              }
              Pair<?, ?> pair = (Pair<?, ?>) o;
              return Objects.equals(fs, pair.fs) && Objects.equals(sc, pair.sc);
          }
  
          public int hashCode() {
              return Objects.hash(fs, sc);
          }
  
      }
  
      static class InputReader {
          private static final int BUFFER_LENGTH = 1 << 10;
          private InputStream stream;
          private byte[] buf = new byte[BUFFER_LENGTH];
          private int curChar;
          private int numChars;
  
          public InputReader(InputStream stream) {
              this.stream = stream;
          }
  
          private int nextC() {
              if (numChars == -1) {
                  throw new InputMismatchException();
              }
              if (curChar >= numChars) {
                  curChar = 0;
                  try {
                      numChars = stream.read(buf);
                  } catch (IOException e) {
                      throw new InputMismatchException();
                  }
                  if (numChars <= 0)
                      return -1;
              }
              return buf[curChar++];
          }
  
          public String next() {
              int c = nextC();
              while (isSpaceChar(c)) {
                  c = nextC();
              }
              StringBuilder res = new StringBuilder();
              do {
                  res.append((char) c);
                  c = nextC();
              } while (!isSpaceChar(c));
              return res.toString();
          }
  
          public int nextInt() {
              int c = skipWhileSpace();
              int sgn = 1;
              if (c == '-') {
                  sgn = -1;
                  c = nextC();
              }
              int res = 0;
              do {
                  if (c < '0' || c > '9') {
                      throw new InputMismatchException();
                  }
                  res *= 10;
                  res += c - '0';
                  c = nextC();
              } while (!isSpaceChar(c));
              return res * sgn;
          }
  
          public int skipWhileSpace() {
              int c = nextC();
              while (isSpaceChar(c)) {
                  c = nextC();
              }
              return c;
          }
  
          public boolean isSpaceChar(int c) {
              return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
          }
  
      }
  }
  
  