input: 
  from typing import List
  
  def averageMatrix(matrix: List[List[int]]) -> float:
      """ Calculate the average of the elements in a 2-dimensional array.
      >>> averageMatrix([[3,2,6],[8,5,9],[4,7,1]])
      4.77
      """
      total = 0
      for row in matrix:
          for element in row:
              total += element
      return total / (len(matrix) * len(matrix[0]))
  
  a = [[3,2,6],
       [8,5,9],
       [4,7,1]]
  
  print(averageMatrix(a)) # 4.77
  
output:     total = 0
      count = 0
      for row in matrix:
          for element in row:
              total += element
              count += 1
      return round(total / count, 2)