new_contents: # It is required to find the position of a slice with min avg in the 
  # numerical sequence. There is a mathematical proof for such problem
  # where only slices of 2 and 3 elements are taken into account.
  # Having that, solution become really simple. 
  def get_prefix_sum(A):
      result = [0] * (len(A) + 1)
      for i in xrange(1, len(A) + 1):
          result[i] = result[i - 1] + A[i - 1]
      return result
  
  def solution(A):
      pref = get_prefix_sum(A)
      min_i = 0
      min_slice = float(A[0] + A[1])/2.0
      for i in xrange(len(A)):
          if i < len(A) - 2:
              slice_3_avg = float(pref[i + 3] - pref[i])/3.0
              if slice_3_avg < min_slice:
                  min_slice = slice_3_avg
                  min_i = i
          if i< len(A) - 1:
              slice_2_avg = float(pref[i + 2] - pref[i])/2.0
              if slice_2_avg < min_slice:
                  min_slice = slice_2_avg
                  min_i = i
      return min_i
  
subject: Add min avg slice solution.