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.BufferedReader;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.PrintWriter;
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Map;
  import java.util.Set;
  import java.util.StringTokenizer;
  
  public class TaskD {
  
      public static void main(String[] arg) {
          final FastScanner in = new FastScanner(System.in);
          final PrintWriter out = new PrintWriter(System.out);
          final int T = in.nextInt();
          for (int t = 0; t < T; t++) {
              int n = in.nextInt();
              int[] a = in.readIntArr(n);
              Solution sol = new Solution(n, a);
              int[] b = sol.solution();
              final StringBuilder res = new StringBuilder();
              for (int i = 0; i < b.length; i++) {
                  res.append(b[i]).append(' ');
              }
              out.println(res.toString());
          }
          out.close();
          in.close();
      }
  
      public static class Solution {
          final int n;
          final int[] a;
  
          public Solution(final int n, final int[] a) {
              this.n = n;
              this.a = a;
          }
  
          public int[] solution() {
              final long sum = calcSum(a);
              return TaskD.solution(a, sum);
          }
  
      }
  
      private static long gcd(long a, long b) {
          if (b == 0) {
              return a;
          }
          return gcd(b, a % b);
      }
  
      private static Map<Integer, Integer> buildCntMap(final int[] a) {
          final Map<Integer, Integer> cntMap = new HashMap<>();
          for (int i = 0; i < a.length; i++) {
              Integer cnt = cntMap.getOrDefault(a[i], 0);
              cntMap.put(a[i], cnt + 1);
          }
          return cntMap;
      }
  
      private static int[] solution(final int[] a, final long sum) {
          final Map<Integer, Integer> cntMap = buildCntMap(a);
          final Set<Integer> visited = new HashSet<>();
          for (int i = 0; i < a.length; i++) {
              if (sum - a[i] == 0) {
                  continue;
              }
              if (visited.contains(a[i])) {
                  continue;
              }
              visited.add(a[i]);
              long gcd = gcd(sum - a[i], a[i]);
              long lcm = (sum - a[i]) * a[i] / gcd;
              long mul1 = lcm / (sum - a[i]);
              long mul2 = lcm / a[i];
              long bSum = mul1 * (a.length - 1) + mul2;
              if (bSum <= 1_000_000_000) {
                  int[] b = new int[a.length];
                  Arrays.fill(b, (int) mul1);
                  b[i] = 0 - (int) mul2;
                  return b;
              }
              if (cntMap.get(a[i]) == 1) {
                  continue;
              }
              int leftNums = cntMap.get(a[i]) - 1;
  //            int removeCnt = 0;
  //            while (leftNums > 0 &&
  //                    bSum > 1_000_000_000) {
  //                removeCnt++;
  //                mul2 -= 2 * mul1;
  //                bSum = mul1 * (a.length - 1) + mul2;
  //            }
              int changeSignCnt = (int) Math.min(mul2 / (2 * mul1), leftNums);
              bSum -= changeSignCnt * 2 * mul1;
              mul2 -= changeSignCnt * 2 * mul1;
  
              if (bSum <= 1_000_000_000) {
                  int[] b = new int[a.length];
                  Arrays.fill(b, (int) mul1);
                  b[i] = 0 - (int) (mul2);
                  for (int j = 0; j < a.length && changeSignCnt > 0; j++) {
                      if (a[j] == a[i] && j != i) {
                          changeSignCnt--;
                          b[j] *= -1;
                      }
                  }
                  return b;
              }
          }
          return null;
      }
  
      public static long calcSum(int a[]) {
          long sum = 0;
          for (int i = 0; i < a.length; i++) {
              sum += a[i];
          }
          return sum;
      }
  
      private static class FastScanner {
          BufferedReader br;
          StringTokenizer st;
  
          FastScanner(InputStream stream) {
              try {
                  br = new BufferedReader(new InputStreamReader(stream));
              } catch (Exception e) {
                  e.printStackTrace();
              }
          }
  
          String next() {
              while (st == null || !st.hasMoreTokens()) {
                  try {
                      st = new StringTokenizer(br.readLine());
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
              }
              return st.nextToken();
          }
  
          int nextInt() {
              return Integer.parseInt(next());
          }
  
          int[] readIntArr(int n) {
              int[] result = new int[n];
              for (int i = 0; i < n; i++) {
                  result[i] = Integer.parseInt(next());
              }
              return result;
          }
  
          long[] readLongArr(int n) {
              long[] result = new long[n];
              for (int i = 0; i < n; i++) {
                  result[i] = Long.parseLong(next());
              }
              return result;
          }
  
          void close() {
              try {
                  br.close();
              } catch (IOException e) {
                  e.printStackTrace();
              }
          }
  
          long nextLong() {
              return Long.parseLong(next());
          }
  
      }
  }
  