input: Write a function to calculate the average of the elements in a 2-dimensional array. If the array is empty or contains no elements, return 0.
  def averageMatrix(matrix):
      if not matrix or not matrix[0]:
          return 0
      total_sum = 0
      count = 0
      for row in matrix:
          for element in row:
              total_sum += element
              count += 1
      return total_sum / count if count > 0 else 0
  
  a = [[3,2,6],
       [8,5,9],
       [4,7,1]]
  
  assert averageMatrix(a) == 5.222222222222222
  assert averageMatrix([]) == 0
  assert averageMatrix([[]]) == 0
  assert averageMatrix([[1, 2, 3], [4, 5, 6]]) == 3.5
  assert averageMatrix([[10, 20], [30, 40]]) == 25.0
output: def averageMatrix(matrix):
      if not matrix or not matrix[0]:
          return 0
      total_sum = 0
      count = 0
      for row in matrix:
          for element in row:
              total_sum += element
              count += 1
      return total_sum / count if count > 0 else 0