input: Write a function that takes a list of integers as input and returns True if the list can be sorted in non-decreasing order by performing any number of right shift operations on the list, otherwise returns False. If the list is empty, return True.
  assert shift_sort([3, 4, 5, 1, 2]) == True
  assert shift_sort([3, 5, 10, 1, 2]) == True
  assert shift_sort([4, 3, 1, 2]) == False
  assert shift_sort([3, 5, 4, 1, 2]) == False
  assert shift_sort([]) == True
output: def shift_sort(lst):
      if not lst:
          return True
      n = len(lst)
      count = 0
      for i in range(n):
          if lst[i] > lst[(i + 1) % n]:
              count += 1
          if count > 1:
              return False
      return True