input: Write a function to find the 2 greatest numbers from a list of integers. If the list has fewer than 2 elements, return a message stating that the list is too short.
  assert get_greatest_2([1, 5, 3, 7, 4, 7, 8, 9, 2, 10, 6, 8])==(10, 9)
  assert get_greatest_2([1, 2])==(2, 1)
  assert get_greatest_2([3, 5, 2, 4, 1])==(5, 4)
  assert get_greatest_2([10])=="The list is too short"
  assert get_greatest_2([])=="The list is too short"
output: def get_greatest_2(lst):
      if len(lst) < 2:
          return "The list is too short"
      sorted_lst = sorted(lst, reverse=True)
      return (sorted_lst[0], sorted_lst[1])