description: You are given n integers a_1, a_2, …, a_n. Find the maximum value of max(a_l, a_{l + 1}, …, a_r) ⋅ min(a_l, a_{l + 1}, …, a_r) over all pairs (l, r) of integers for which 1 ≤ l < r ≤ n.
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 10 000) — the number of test cases.
  
  The first line of each test case contains a single integer n (2 ≤ n ≤ 10^5).
  
  The second line of each test case contains n integers a_1, a_2, …, a_n (1 ≤ a_i ≤ 10^6).
  
  It is guaranteed that the sum of n over all test cases doesn't exceed 3 ⋅ 10^5.
  
  Output
  
  For each test case, print a single integer — the maximum possible value of the product from the statement.
  
  Example
  
  Input
  
  
  4
  3
  2 4 3
  4
  3 2 3 1
  2
  69 69
  6
  719313 273225 402638 473783 804745 323328
  
  
  Output
  
  
  12
  6
  4761
  381274500335
  
  Note
  
  Let f(l, r) = max(a_l, a_{l + 1}, …, a_r) ⋅ min(a_l, a_{l + 1}, …, a_r).
  
  In the first test case, 
  
    * f(1, 2) = max(a_1, a_2) ⋅ min(a_1, a_2) = max(2, 4) ⋅ min(2, 4) = 4 ⋅ 2 = 8. 
    * f(1, 3) = max(a_1, a_2, a_3) ⋅ min(a_1, a_2, a_3) = max(2, 4, 3) ⋅ min(2, 4, 3) = 4 ⋅ 2 = 8. 
    * f(2, 3) = max(a_2, a_3) ⋅ min(a_2, a_3) = max(4, 3) ⋅ min(4, 3) = 4 ⋅ 3 = 12. 
  
  
  
  So the maximum is f(2, 3) = 12.
  
  In the second test case, the maximum is f(1, 2) = f(1, 3) = f(2, 3) = 6.
solution: if __name__ == "__main__":
      tcase = int(input().strip())
      for _ in range(tcase):
          n = int(input().strip())
          nums = list(map(int, input().strip().split()))
          maxpos, minpos = 0, 0
          if nums[1] > nums[0]:
              maxpos = 1
          else:
              minpos = 1
          prodmax = nums[0] * nums[1]
          for i in range(2, n):
              if maxpos is None:
                  if nums[i] > nums[minpos]:
                      maxpos = i
                  else:
                      minpos, maxpos = i, minpos
                  prodmax = max(prodmax, nums[minpos] * nums[maxpos])
                  continue
              if nums[i] >= nums[maxpos]:
                  if maxpos > minpos:
                      maxpos, minpos = i, maxpos
                  else:
                      maxpos = i
                  # print(minpos, maxpos)
                  prodmax = max(prodmax, nums[minpos] * nums[maxpos])
              elif nums[i] > nums[minpos]:
                  if maxpos > minpos:
                      minpos = i
                      prodmax = max(prodmax, nums[minpos] * nums[maxpos])
                  else:
                      minpos, maxpos = i, None
              else:
                  minpos, maxpos = i, None
          print(prodmax)
  
  
  