output_description: Print the answer.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      a_{0} a_{1} ... a_{N-1}
attempt: def main():
      n = input()
      data = input().split()
      data = list(map(lambda x: int(x), data))
  
      mid_val = calculate_mean(data)
  
      if int(n) < 1 or 101 < int(n):
          return -1
  
      current_pos = -1
      current_distance = 101
  
      if int(n) == len(data):
          for key, value in enumerate(data):
              if int(value) < 1 or 101 < int(value):
                  return -1
              new_distance = abs(mid_val - value)
              if current_distance > new_distance:
                  current_pos = key
                  current_distance = new_distance
          return current_pos
  
  
  def calculate_mean(data):
      s = sum(data)
      N = len(data)
      mean = s / N
  
      return mean
  
  
  r = main()
  print(r)
  
problem_description: Statement
  
  Niwango-kun is an employee of Dwango Co., Ltd.  
  One day, he is asked to generate a thumbnail from a video a user submitted.  
  To generate a thumbnail, he needs to select a frame of the video according to
  the following procedure:
  
    * Get an integer N and N integers a_0, a_1, ..., a_{N-1} as inputs. N denotes the number of the frames of the video, and each a_i denotes the representation of the i-th frame of the video.
    * Select t-th frame whose representation a_t is nearest to the average of all frame representations.
    * If there are multiple such frames, select the frame with the smallest index.
  
  Find the index t of the frame he should select to generate a thumbnail.
samples: [{"input": "3\n    1 2 3", "output": "1\n    \n\nSince the average of frame representations is 2, Niwango-kun needs to select\nthe index 1, whose representation is 2, that is, the nearest value to the\naverage.\n\n* * *"}, {"input": "4\n    2 5 2 5", "output": "0\n    \n\nThe average of frame representations is 3.5.  \nIn this case, every frame has the same distance from its representation to the\naverage.  \nTherefore, Niwango-kun should select index 0, the smallest index among them."}]