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: def main():
      alpha = 'abcdefghijklmnopqrstuvwxyz'
      ALPHA = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
      inf = 1e17
      # mod = 998244353
      mod = 10 ** 9 + 7
  
      # Max = 10 ** 6
      # primes = []
      # prime = [True for i in range(Max + 1)]
      # p = 2
      # while (p * p <= Max + 1):
      #
      #     # If prime[p] is not
      #     # changed, then it is a prime
      #     if (prime[p] == True):
      #
      #         # Update all multiples of p
      #         for i in range(p * p, Max + 1, p):
      #             prime[i] = False
      #     p += 1
      #
      # for p in range(2, Max + 1):
      #     if prime[p]:
      #         primes.append(p)
  
      #print(len(primes))
  
  
      def factorial(n):
          f = 1
  
          for i in range(1, n + 1):
              f = (f * i) % mod  # Now f never can
          # exceed 10^9+7
  
          return f
  
      def factorial_by(n,by):
          f = 1
  
          for i in range(1,n+1):
              if i == by:
                  continue
              f = (f * i) % mod  # Now f never can
          # exceed 10^9+7
  
          return f
  
      def ncr(n, r):
          # initialize numerator
          # and denominator
          num = den = 1
          for i in range(r):
              num = (num * (n - i)) % mod
              den = (den * (i + 1)) % mod
          return (num * pow(den,
                            mod - 2, mod)) % mod
  
      def primeFactors(num):
  
          pf = []
          while num % 2 == 0:
              pf.append(2)
              num = num // 2
  
          # n must be odd at this point
          # so a skip of 2 ( i = i + 2) can be used
          for i in range(3, int(math.sqrt(num)) + 1, 2):
  
              # while i divides n , print i and divide n
              while num % i == 0:
                  pf.append(i)
                  num = num // i
  
          # Condition if n is a prime
          # number greater than 2
          if num > 2:
              pf.append(num)
  
          return pf
  
      class Node(object):
          def __init__(self, name,d):
              self.d = d
              self.name = name
  
          def __repr__(self):
              pass
  
  
  
      def solve(n,a):
  
          if n % 2:
              b = []
              for i in range(0,n-3,2):
                  b.append(-a[i+1])
                  b.append(a[i])
              b.append(0)
              b.append(0)
              b.append(0)
              if a[n - 3] != a[n-2]:
                  b[n - 3] = -a[n-1]
                  b[n - 2] = a[n-1]
                  b[n - 1] = a[n-3]-a[n-2]
              elif a[n - 3] != a[n-1]:
  
                  b[n - 3] = -a[n-2]
                  b[n - 2] = a[n - 3] - a[n-1]
                  b[n - 1] = a[n-2]
  
              elif a[n - 1] != a[n-2]:
  
                  b[n-3] = a[n-2]-a[n-1]
                  b[n-2] = -a[n-3]
                  b[n-1] = a[n-3]
              else:
                  b[n - 3] = 1
                  b[n - 2] = 1
                  b[n - 1] = -2
              return (" ".join(list(map(str,b))))
  
          else:
              b = []
              for i in range(0, n, 2):
                  b.append(-a[i + 1])
                  b.append(a[i])
              return (" ".join(list(map(str, b))))
  
  
  
  
      t = int(input())
      ans = []
      for _ in range(t):
          #s = list(input()[:-1])
          n = int(input())
  
          #n,k = map(int, input().split())
          a = [int(x) for x in input().split()]
          #s = list(map(int,list(input()[:-1])))
          #a = [int(x) for x in input().split()]
          #b = [int(x) for x in input().split()]
          # q = int(input())
          # queries = []
          # for i in range(q):
          #     x,k = map(int, input().split())
          #     queries.append([x,k])
  
  
          # tree = []
          # degrees = [0]*(n+1)
          #
          # for i in range(n+1):
          #     tree.append([])
          #
          # for i in range(n-1):
          #     u, v = map(int, input().split())
          #     tree[u].append(v)
          #     tree[v].append(u)
  
  
  
  
          ans.append(solve(n,a))
  
      p = 1
      for answer in ans:
          #print('Case #'+str(p)+": "+str(answer))
          print(answer)
          p += 1
  
  
  if __name__ == "__main__":
      import sys, threading
      import bisect
      import math
      import itertools
      from sys import stdout
  
  
      ############  Sorted Containers  ######################
      import heapq
      from queue import PriorityQueue
      from collections import deque
  
  
      ############ Tree Problems ( Use Python 3) ###########
      sys.setrecursionlimit(2 ** 32 // 2 - 1)
      threading.stack_size(1 << 27)
  
      input = sys.stdin.readline
      thread = threading.Thread(target=main)
      thread.start()
      thread.join()