output_description: Print the maximum possible distance of A and B.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      P_0 P_1 \cdots P_{N-1}
      Q_0 Q_1 \cdots Q_{N-1}
attempt: N = int(input())
  Pn = list(map(int, input().split(" ")))
  Qn = list(map(int, input().split(" ")))
  
  # print(Pn)
  # print(Qn)
  
  GenPn = [x for x in range(N)]
  # print(GenPn)
  
  
  def distance(Pn, Qn):
      d = 0
      for i in range(len(Pn)):
          if Pn[i] != Qn[i]:
              d = d + 1
      return d
  
  
  answer = distance(Pn, Qn)
  answer = max(answer, distance(Pn, GenPn))
  answer = max(answer, distance(GenPn, Qn))
  
  print(answer)
  
problem_description: Statement
  
  Snuke has permutations (P_0,P_1,\cdots,P_{N-1}) and (Q_0,Q_1,\cdots,Q_{N-1})
  of (0,1,\cdots,N-1).
  
  Now, he will make new permutations A and B of (0,1,\cdots,N-1), under the
  following conditions:
  
    * For each i (0 \leq i \leq N-1), A_i should be i or P_i.
    * For each i (0 \leq i \leq N-1), B_i should be i or Q_i.
  
  Let us define the distance of permutations A and B as the number of indices i
  such that A_i \neq B_i. Find the maximum possible distance of A and B.
samples: [{"input": "4\n    2 1 3 0\n    0 2 3 1", "output": "3\n    \n\nFor example, if we make A=(0,1,2,3) and B=(0,2,3,1), the distance will be 3,\nwhich is the maximum result possible.\n\n* * *"}, {"input": "10\n    0 4 5 3 7 8 2 1 9 6\n    3 8 5 6 4 0 2 1 7 9", "output": "8\n    \n\n* * *"}, {"input": "32\n    22 31 30 29 7 17 16 3 14 9 19 11 2 5 10 1 25 18 15 24 20 0 12 21 27 4 26 28 8 6 23 13\n    22 3 2 7 17 9 16 4 14 8 19 26 28 5 10 1 25 18 15 13 11 0 12 23 21 20 29 24 27 6 30 31", "output": "28"}]