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 sys
  import math
  import random
  import heapq
  #sys.setrecursionlimit(10**6)
  input=sys.stdin.readline
  def pow(a,n,m):
      if n==0:
          return 1 
      x=pow(a,n//2,m)
      if n%2==0 :
          return (x*x)%m 
      else:
          return (x*x*a)%m
   
  def gcd(a,b):
      while b!=0:
          a,b=b,a%b
      return a 
      
  def bs(arr,le,ri):
      l=0
      arr.sort()
      r=len(arr)-1
      ans=10000000
      while l<=r:
          m=(l+r)//2
          if arr[m]>=le and arr[m]<=ri:
              ans=arr[m]
              r=m-1
          elif arr[m]<le:
              l=m+1 
          else:
              r=m-1
      return ans
   
  t=int(input())
  # t=1000
  while t>0:
      n=int(input())
      # n=1000
      a=list(map(int,input().split()))
      # a=[random.randint(1,10000) for i in range(n)]
      b=[1]*n
      s=a[0]
      for i in range(1,n):
          if s*a[i]>0:
              b[i]=-1 
              s-=a[i]
          else:
              s+=a[i]
      # print(b)
      if s!=0:
          c=100000
          ind=-1
          for i in range(n):
              if s-a[i]*b[i]!=0 and abs(s-a[i]*b[i])<c:
                  c=a[i]*b[i]
                  ind=i
          for i in range(n):
              if i==ind:
                  b[i]*=(s-c) 
              else:
                  b[i]*=(-1*c) 
      print(" ".join(map(str,b)))
      s=0 
      c=0
      for i in range(n):
          c+=abs(b[i])
          s+=a[i]*b[i]
      if c>1000000000:
         while True:
             pass
      t-=1