input: Write a function to print all elements in the given list that are greater than 50. If the list is empty, print "The list is empty.". The function should be named `print_numbers_greater_than_50`.
  assert print_numbers_greater_than_50([2, 60, 5, 4, 78, 32, 99])
  60
  78
  99
  assert print_numbers_greater_than_50([55, 67, 20, 45, 70])
  55
  67
  70
  assert print_numbers_greater_than_50([])
  The list is empty.
output: def print_numbers_greater_than_50(lst):
      if not lst:
          print("The list is empty.")
      else:
          for num in lst:
              if num > 50:
                  print(num)