output_description: Print the minimum number of elements that needs to be replaced.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      n
      v_1 v_2 ... v_n
attempt: from collections import Counter
  n = int(input())
  v = list(map(int, input().split()))
  gu = v[::2]
  ki = v[1::2]
  ans = 0
  k,g = False,False
  
  ###全部同じなら全長の半分,
  # 最頻値が同じなら2番目を比べる
  if v.count(v[0]) == n
      ans += n // 2
  else:
      kic = Counter(ki)
      guc = Counter(gu)
      k1 = kic.most_common(2)
      g1 = guc.most_common(2)
      if k1[0][0] == g1[0][0]:
          if k1[1][1] < g1[1][1]:
              g = True
          else:
              k = True
  
      kic = list(kic.values())
      guc = list(guc.values())
      kic.sort(reverse = True)
      guc.sort(reverse = True)
      if len(kic) != 1:
          if k:
              ans += kic[0]
              ans += sum(kic[2::])
          else:
              ans += sum(kic[1::]) 
      if len(guc) != 1:
          if g:
              ans += guc[0]
              ans += sum(guc[2::])
          else:
              ans += sum(guc[1::])
  
  print(ans)
problem_description: Statement
  
  A sequence a_1,a_2,... ,a_n is said to be /\/\/\/ when the following
  conditions are satisfied:
  
    * For each i = 1,2,..., n-2, a_i = a_{i+2}.
    * Exactly two different numbers appear in the sequence.
  
  You are given a sequence v_1,v_2,...,v_n whose length is even. We would like
  to make this sequence /\/\/\/ by replacing some of its elements. Find the
  minimum number of elements that needs to be replaced.
samples: [{"input": "4\n    3 1 3 2", "output": "1\n    \n\nThe sequence 3,1,3,2 is not /\\/\\/\\/, but we can make it /\\/\\/\\/ by replacing\none of its elements: for example, replace the fourth element to make it\n3,1,3,1.\n\n* * *"}, {"input": "6\n    105 119 105 119 105 119", "output": "0\n    \n\nThe sequence 105,119,105,119,105,119 is /\\/\\/\\/.\n\n* * *"}, {"input": "4\n    1 1 1 1", "output": "2\n    \n\nThe elements of the sequence 1,1,1,1 are all the same, so it is not /\\/\\/\\/."}]