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 math
  import os
  import sys
  from io import BytesIO, IOBase
  from types import GeneratorType
  from collections import defaultdict
  BUFSIZE = 8192
  from bisect import bisect_left
  from bisect import bisect_right
  
  
  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")
  
  
  
  t=int(input())
  for _ in range(t):
      n=int(input())
      #a,b,c=map(int,input().split())
      b=list(map(int,input().split()))
      ans=[]
      if(n%2==0):
  
          i=0
          while(i<n):
              ans.append(b[i+1])
              ans.append(-b[i])
              i+=2
  
      else:
          if(b[0]==b[1]):
              if(b[2]==10000):
                  ans.append(1)
                  ans.append(b[2]-1)
                  ans.append(-b[0])
              elif(b[2]==-1):
                  ans.append(1)
                  ans.append(b[2] - 1)
                  ans.append(-b[0])
  
              else:
                  ans.append(-1)
                  ans.append(b[2]+1)
                  ans.append(-b[0])
          if((len(ans)==0) and (b[0]+b[1]==0)):
              if(b[2]==1):
                  ans.append(1)
                  ans.append(b[2]+1)
                  ans.append(b[0])
              elif (b[2]==-1):
                  ans.append(-1)
                  ans.append(b[2] - 1)
                  ans.append(b[0])
  
              elif(b[2]!=10000):
                  ans.append(1)
                  ans.append(b[2]+1)
                  ans.append(b[0])
  
  
              else:
  
                  ans.append(-1)
                  ans.append(b[2] - 1)
                  ans.append(b[0])
  
  
          if(len(ans)==0):
              poss=[-b[0]+b[1],b[0]-b[1],b[0]+b[1],-b[0]-b[1]]
  
  
  
              if(abs(poss[0])<=10000):
                  ans.append(-b[2])
                  ans.append(b[2])
                  ans.append(-poss[0])
  
              elif(abs(poss[1])<=10000):
                  ans.append(b[2])
                  ans.append(-b[2])
                  ans.append(-poss[1])
              elif(abs(poss[2])<=10000):
                  ans.append(b[2])
                  ans.append(b[2])
                  ans.append(-poss[2])
              elif(abs(poss[3])<=10000):
                  ans.append(-b[2])
                  ans.append(-b[2])
                  ans.append(-poss[3])
  
  
          i=3
          while(i<n):
              ans.append(b[i+1])
              ans.append(-b[i])
              i+=2
      print(*ans)
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  