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: # cook your dish here
  import sys
  import bisect
  from bisect import bisect_left as lb
  from bisect import bisect_right as rb
  input_=lambda: sys.stdin.readline().strip("\r\n")
  from math import log
  from math import gcd
  from math import atan2,acos
  from random import randint
  sa=lambda :input_()
  sb=lambda:int(input_())
  sc=lambda:input_().split()
  sd=lambda:list(map(int,input_().split()))
  sflo=lambda:list(map(float,input_().split()))
  se=lambda:float(input_())
  sf=lambda:list(input_())
  flsh=lambda: sys.stdout.flush()
  #sys.setrecursionlimit(10**7)
  mod=10**9+7
  mod1=998244353
  gp=[]
  cost=[]
  dp=[]
  mx=[]
  ans1=[]
  ans2=[]
  special=[]
  specnode=[]
  a=0
  kthpar=[]
  def dfs2(root,par):
      if par!=-1:
          dp[root]=dp[par]+1
      for i in range(1,20):
          if kthpar[root][i-1]!=-1:
              kthpar[root][i]=kthpar[kthpar[root][i-1]][i-1]
      for child in gp[root]:
          if child==par:continue
          kthpar[child][0]=root
          dfs(child,root)
          
  ans=0
  a=[]
  n,k=0,0
  b=[]
  vis=[]
  tot=0
  time=[]
  time1=[]
  adj=[]
  mx=-1
  eps=0.0000001
  x=0
  pref=[]
  lvl=[]
  #Fenwick Tree point update range sum
  def update_it(bit,i,val):
      n=len(bit)
      while(i<n):
          bit[i]+=val
          i+=i&(-i)
  def get_ans(bit,i):
      n=len(bit)
      tot=0
      while(i>0):
          tot+=bit[i]
          i-=i&(-i)
      return tot
  def hnbhai(tc):
      n=sb()
      a=sd()
      b=[0]*n
      for i in range(1,n,2):
          b[i]=-a[i-1]
          b[i-1]=a[i]
      if n%2==0:
          print(*b)
          return
      #b=[1]*n
      if n<=3:
          x=sum(a)
          ind=0
          b=[1]*n
          for i in range(n):
              if x-a[i]!=0:
                  if abs(a[i])*(n-1)+abs(x-a[i])<=10**9:            
                      ind=a[i]
                      b=[ind]*n
                      b[i]=-(x-a[i])
                      break    
          print(*b)
          return
      x=a[-1]+a[-2]+a[-3]
      ind=0
      for i in range(n-3,n):
          if x-a[i]!=0:
              if abs(a[i])*(2)+abs(x-a[i])<=10**9:            
                  ind=a[i]
                  b[-1]=b[-2]=b[-3]=ind
                  b[i]=-(x-a[i])
                  break
      print(*b)
  for _ in range(sb()):
      hnbhai(_+1)
  