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: from __future__ import division, print_function
  
  import itertools
  import sys
  from atexit import register
  
  if sys.version_info[0] < 3:
      from io import BytesIO as stream
  else:
      from io import StringIO as stream
  
  if sys.version_info[0] < 3:
      class dict(dict):
          """dict() -> new empty dictionary"""
  
          def items(self):
              """D.items() -> a set-like object providing a view on D's items"""
              return dict.iteritems(self)
  
          def keys(self):
              """D.keys() -> a set-like object providing a view on D's keys"""
              return dict.iterkeys(self)
  
          def values(self):
              """D.values() -> an object providing a view on D's values"""
              return dict.itervalues(self)
  
      input = raw_input
      range = xrange
  
      filter = itertools.ifilter
      map = itertools.imap
      zip = itertools.izip
  
  
  def sync_with_stdio(sync=True):
      """Set whether the standard Python streams are allowed to buffer their I/O.
  
      Args:
          sync (bool, optional): The new synchronization setting.
  
      """
      global input, flush
  
      if sync:
          flush = sys.stdout.flush
      else:
          sys.stdin = stream(sys.stdin.read())
          def input(): return sys.stdin.readline().rstrip('\r\n')
  
          sys.stdout = stream()
          register(lambda: sys.__stdout__.write(sys.stdout.getvalue()))
  
  
  mod = 1000000007
  
  
  # Code From Here
  
  for _ in range(int(input())):
      n = int(input())
      a = list(map(int, input().split()))
      ans = 1
      for i in range(n-1):
          ans = max(ans, a[i]*a[i+1])
      print(ans)
  