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 os
  import sys
  from io import BytesIO, IOBase
  
  _str = str
  str = lambda x=b"": x if type(x) is bytes else _str(x).encode()
  
  BUFSIZE = 8192
  
  
  def sigma1(a):
      return sum(a)
  def sigma2(a):
      return sum([i*i for i in a])
  def sigma3(a):
      return sum([i*i*i for i in a])
  def prodofpairs(a):
      return (sigma1(a)**2-sigma2(a))//2
  def prodoftriplets(a):
      return (sigma1(a)**3-3*sigma1(a)*sigma2(a)+2*sigma3(a))//6
  from collections import Counter,defaultdict
  from math import gcd
  from collections import deque
  def bfs(graph, start=0):
      used = [False] * len(graph)
      used[start] = True
      q = [start]
      for v in q:
          for w in graph[v]:
              if not used[w]:
                  used[w] = True
                  q.append(w)
  
  
  def layers(graph, start=0):
      used = [False] * len(graph)
      used[start] = True
      q, ret = [start], []
      level=[0]*len(graph)
      while q:
          nq = []
          ret.append(q)
          for v in q:
              for w in graph[v]:
                  if not used[w]:
                      used[w] = True
                      nq.append(w)
                      level[w]=1+level[v]
          q = nq
      return level
  
  import math
   
  # function to find GCD of sub sequence
  # of size k with max GCD in the array
  def findMaxGCD(arr, n, k):
      high = max(arr)
      divisors = [0] * (high + 1)
      for i in range(n) :
          for j in range(1, int(math.sqrt(arr[i])) + 1):
              if (arr[i] % j == 0) :
                  divisors[j] += 1
                  if (j != arr[i] // j):
                      divisors[arr[i] // j] += 1
      for i in range(high, 0, -1):
          if (divisors[i] >= k):
              return i
  def xdist(a,b):
      if(b[0]>=a[0]>=b[2] or b[0]<=a[0]<=b[2] ):
          return 0
      return min(abs(a[0]-b[0]),abs(a[0]-b[2]))
  def ydist(a,b):
      if(b[1]>=a[1]>=b[3] or b[1]<=a[1]<=b[3] ):
          return 0
      return min(abs(a[1]-b[1]),abs(a[1]-b[3]))
  def countdistx(i,j,k,obj):
      m=0
      for i1 in range(k):
          m+=xdist([i,j],obj[i1])
      return m
  def countdisty(i,j,k,obj):
      m=0
      for i1 in range(k):
          m+=ydist([i,j],obj[i1])
      return m
  from bisect import bisect_left
  def dp(i,n,cost,a):
      if(cost==0):
          return 0
      if(cost<0):
          return float("Inf")
      l=[float("Inf")]
      for j in range(i,n+1):
          k=bisect_left(a,a[j]+cost,j)
          if(k<=n and a[k]==a[j]+cost):
              l.append(k-j)
      return min(l)
  def isp(x):
      for i in range(2,int(math.sqrt(x))+1):
          if(x%i==0):
              return False
      return True
  from bisect import bisect_right
  from sys import stdout
  def sol(s,c,i,j):
      a=s
      count=0
      while(i<j):
          if(a[i]==a[j]):
              i+=1
              j-=1
          elif(a[i]==c):
              i+=1
              count+=1
          elif(a[j]==c):
              j-=1
              count+=1
          else:
              return -1
      return count
  def main():
      for _ in range(int(input())):
          n=int(input())
          a=list(map(int,input().split()))
          s=0
          m=abs(min(a,key=lambda x:abs(x)))
          x=0
          l=[1]*n
          for i in range(n):
              if(i%2==0):
                  l[i]=1
                  s+=a[i]
              else:
                  s-=a[i]
                  l[i]=-1
          for i in range(n):
              if(i%2==0 and s-a[i]!=0):
                  l[i]=-(s-a[i])
                  for j in range(n):
                      if(i!=j):
                          l[j]=l[j]*a[i]
                  print(*l)
                  break
              elif(i%2==1 and s+a[i]!=0):
                  l[i]=-(s+a[i])
                  for j in range(n):
                      if(i!=j):
                          l[j]=l[j]*a[i]
                  print(*l)
                  break
  
  
  
  
      
  
  
  
              
  
  
  
      
          
          
              
  
  
  
  
          
  
  
  
  
  
          
  
  
          
  
  main()
  
  class FastIO(IOBase):
      newlines = 0
  
      def __init__(self, file):
          self._fd = file.fileno()
          self.buffer = BytesIO()
          self.writable = "x" in file.mode or "r" not in file.mode
          self.write = self.buffer.write if self.writable else None
  
      def read(self):
          while True:
              b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
              if not b:
                  break
              ptr = self.buffer.tell()
              self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
          self.newlines = 0
          return self.buffer.read()
  
      def readline(self):
          while self.newlines == 0:
              b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
              self.newlines = b.count(b"\n") + (not b)
              ptr = self.buffer.tell()
              self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
          self.newlines -= 1
          return self.buffer.readline()
  
      def flush(self):
          if self.writable:
              os.write(self._fd, self.buffer.getvalue())
              self.buffer.truncate(0), self.buffer.seek(0)
  
  
  class IOWrapper(IOBase):
      def __init__(self, file):
          self.buffer = FastIO(file)
          self.flush = self.buffer.flush
          self.writable = self.buffer.writable
          self.write = lambda s: self.buffer.write(s.encode("ascii"))
          self.read = lambda: self.buffer.read().decode("ascii")
          self.readline = lambda: self.buffer.readline().decode("ascii")
  
  
  sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
  input = lambda: sys.stdin.readline().rstrip("\r\n")
  
  
  
  
  