output_description: If the objective is achievable, print the minimum necessary number of
  operations. Otherwise, print `-1` instead.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      a_1 a_2 ... a_N
      b_1 b_2 ... b_N
attempt: print(-1)
  
problem_description: Statement
  
  There is a sequence of length N: a = (a_1, a_2, ..., a_N). Here, each a_i is a
  non-negative integer.
  
  Snuke can repeatedly perform the following operation:
  
    * Let the XOR of all the elements in a be x. Select an integer i (1 ≤ i ≤ N) and replace a_i with x.
  
  Snuke's objective is to match a with another sequence b = (b_1, b_2, ...,
  b_N). Here, each b_i is a non-negative integer.
  
  Determine whether the objective is achievable, and find the minimum necessary
  number of operations if the answer is positive.
samples: [{"input": "3\n    0 1 2\n    3 1 0", "output": "2\n    \n\nAt first, the XOR of all the elements of a is 3. If we replace a_1 with 3, a\nbecomes (3, 1, 2).\n\nNow, the XOR of all the elements of a is 0. If we replace a_3 with 0, a\nbecomes (3, 1, 0), which matches b.\n\n* * *"}, {"input": "3\n    0 1 2\n    0 1 2", "output": "0\n    \n\n* * *"}, {"input": "2\n    1 1\n    0 0", "output": "-1\n    \n\n* * *"}, {"input": "4\n    0 1 2 3\n    1 0 3 2", "output": "5"}]