input: from typing import List
  
  
  def averageMatrix(matrix: List[List[int]]) -> float:
      """ Calculate the average of all elements in a 2-dimensional array.
      >>> a = [[3,2,6], [8,5,9], [4,7,1]]
      >>> 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)