input: Write a python function to count the number of elements in a 2D list that are greater than 5.
  assert count_elements_greater_than_five([[1, 6, 3], [7, 5, 9], [4, 2, 8]]) == 4
  assert count_elements_greater_than_five([[1, 2, 3], [4, 5, 6], [7, 8, 9]]) == 4
  assert count_elements_greater_than_five([[10, 20], [30, 40], [50, 60]]) == 6
output: def count_elements_greater_than_five(matrix):
      count = 0
      for row in matrix:
          for element in row:
              if element > 5:
                  count += 1
      return count