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: def cal(n, v):
      k = n // 2
      even = range(0, 2 * k, 2)
      odd = range(1, 2 * k + 1, 2)
  
      el = []
      for i in even:
          el.append(v[i])
      ol = []
      for i in odd:
          ol.append(v[i])
  
      d = {}
      for i in el:
          if (i in d) is False:
              d[i] = 0
          else:
              d[i] += 1
  
      f = {}
      for i in ol:
          if (i in f) is False:
              f[i] = 0
          else:
              f[i] += 1
  
      while True:
          e = max(d, key=d.get)
          o = max(f, key=f.get)
          if e == o:
              if d[e] > f[o]:
                  del f[o]
              elif d[e] < f[o]:
                  del d[e]
              else:
                  return print(k)
          else:
              break
  
      sum = 0
      for i in el:
          if i != e:
              sum += 1
      for i in ol:
          if i != o:
              sum += 1
      return print(sum)
  
  
  n = int(input())
  v = list(map(int, input().split()))
  cal(n, v)
  
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 /\\/\\/\\/."}]