output_description: Print the answer.
  
  * * *
input_description: The input is given from Standard Input in the following format:
  
      
      
      N
      A_1 A_2 A_3 ... A_{N}
attempt: n = input()
  n = int(n)
  ss = input().split()
  sslist = sorted(ss)
  # print(sslist)
  dic_ss = {}
  for x in sslist:
      dic_ss.setdefault(x, 0)
      dic_ss[x] += 1
  # print(dic_ss)
  # 1) 3回以上の重複があれば、その数字だけを使って、排除 N -> N-2
  for key, value in dic_ss.items():
      while value >= 3:
          value -= 2
      dic_ss[key] = value
  # print(dic_ss)
  # 2) 2回重複の最小値と最大値を使って重複排除 Min N -> N-1, Max M -> M-1
  key1 = None
  key2 = None
  for key, value in dic_ss.items():
      if key1 == None and value == 2:
          key1 = key
      elif key2 == None and value == 2:
          key2 = key
      if key1 != None and key2 != None:
          dic_ss[key1] = 1
          dic_ss[key2] = 1
          key1 = None
          key2 = None
  # print(dic_ss)
  # 3) 2回重複が1つ残ったら、重複なしから1つ削除
  count = len(dic_ss)
  for key, value in dic_ss.items():
      if value > 1:
          count -= 1
  print(count)
  
problem_description: Statement
  
  Snuke has decided to play a game using cards. He has a deck consisting of N
  cards. On the i-th card from the top, an integer A_i is written.
  
  He will perform the operation described below zero or more times, so that the
  values written on the remaining cards will be pairwise distinct. Find the
  maximum possible number of remaining cards. Here, N is odd, which guarantees
  that at least one card can be kept.
  
  Operation: Take out three arbitrary cards from the deck. Among those three
  cards, eat two: one with the largest value, and another with the smallest
  value. Then, return the remaining one card to the deck.
samples: [{"input": "5\n    1 2 1 3 7", "output": "3\n    \n\nOne optimal solution is to perform the operation once, taking out two cards\nwith 1 and one card with 2. One card with 1 and another with 2 will be eaten,\nand the remaining card with 1 will be returned to deck. Then, the values\nwritten on the remaining cards in the deck will be pairwise distinct: 1, 3 and\n7.\n\n* * *"}, {"input": "15\n    1 3 5 2 1 3 2 8 8 6 2 6 11 1 1", "output": "7"}]