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: #111c
  import collections
  import copy
  
  n = int(input()) #2≤n≤10**5 偶数
  v_list = [int(e) for e in input().split()]
  
  #数列 a1,a2,...,anが以下の条件を満たすとき、 /\/\/\/ と呼ぶことにします。
  
  #・各 i=1,2,...,n−2について、ai=ai+2 
  #・数列に現れる数はちょうど 2種類
  
  #偶数長の数列 v1,v2,...,vnが与えられます。 
  #要素をいくつか書き換えることでこの数列を /\/\/\/ にしたいです。 書き換える要素の数は最小でいくつになるか求めてください。
  
  #一番多く出てくる文字を求め、書き換えない数字を決める
  v_list_odd = [v_list[i] for i in range(n) if i%2==1]
  v_list_even = [v_list[i] for i in range(n) if i%2==0]
  
  #print(v_list_odd)
  #print(v_list_even)
  
  c = collections.Counter(v_list_odd)
  v_list_odd_counter = copy.copy(c)
  if len(c)>1:
      fix_picklist_for_v_list_odd = [((c.most_common(2))[0])[0],((c.most_common(2))[0])[1],((c.most_common(2))[1])[0],((c.most_common(2))[1])[1]]
  else:
      fix_char_for_v_list_odd = fix_picklist_for_v_list_odd = [((c.most_common(2))[0])[0],((c.most_common(2))[0])[1]]
      
  c = collections.Counter(v_list_even)
  v_list_even_counter = copy.copy(c)
  if len(c)>1:
      fix_picklist_for_v_list_even = [((c.most_common(2))[0])[0],((c.most_common(2))[0])[1],((c.most_common(2))[1])[0],((c.most_common(2))[1])[1]]
  else:
      fix_picklist_for_v_list_even = [((c.most_common(2))[0])[0],((c.most_common(2))[0])[1]]
      
  #固定文字の決定
  #1文字目が重複していなければ、両方とも出現回数最多を固定する
  if fix_picklist_for_v_list_even[0] != fix_picklist_for_v_list_odd[0]:
      fix_char_for_v_list_even = fix_picklist_for_v_list_even[0]
      fix_char_for_v_list_odd = fix_picklist_for_v_list_odd[0]
  
  #1文字目が重複している場合
  #両方1文字しかなければ片方のみ
  elif len(fix_picklist_for_v_list_even) == 2 and len(fix_picklist_for_v_list_odd) == 2:
      fix_char_for_v_list_even = fix_picklist_for_v_list_even[0]
      fix_char_for_v_list_odd = "!"
  #片方が1文字ならば、そうでない方は2文字目を使う。
  elif len(fix_picklist_for_v_list_even) == 2 and len(fix_picklist_for_v_list_odd) != 2:
      fix_char_for_v_list_even = fix_picklist_for_v_list_even[0]
      fix_char_for_v_list_odd = fix_picklist_for_v_list_odd[2]
  elif len(fix_picklist_for_v_list_even) != 2 and len(fix_picklist_for_v_list_odd) == 2:
      fix_char_for_v_list_even = fix_picklist_for_v_list_even[2]
      fix_char_for_v_list_odd = fix_picklist_for_v_list_odd[0]
  #両方2文字あるなら、固定パターンの合計が多い方を採用
  elif fix_picklist_for_v_list_even[1] + fix_picklist_for_v_list_odd[3] > fix_picklist_for_v_list_even[3]+fix_picklist_for_v_list_odd[1]:
      fix_char_for_v_list_even = fix_picklist_for_v_list_even[0]
      fix_char_for_v_list_odd = fix_picklist_for_v_list_odd[2]
  elif fix_picklist_for_v_list_even[1] + fix_picklist_for_v_list_odd[3] =< fix_picklist_for_v_list_even[3]+fix_picklist_for_v_list_odd[1]:
      fix_char_for_v_list_even = fix_picklist_for_v_list_even[2]
      fix_char_for_v_list_odd = fix_picklist_for_v_list_odd[0]
  
  #print(fix_char_for_v_list_odd)
  #print(fix_char_for_v_list_even)
          
  #書き換え要素数をカウント
  ans_odd = n/2 - v_list_odd_counter[fix_char_for_v_list_odd]
  ans_even = n/2 - v_list_even_counter[fix_char_for_v_list_even]
  print(int(ans_odd + ans_even))
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 /\\/\\/\\/."}]