Q: In this task, you are given an input list A comprising of numbers and alphabets. You need to extract and sort the unique alphabets in the list. The alphabets in the input list will only be in lowercase. Return -1 if there is no alphabet in the input list.
['9169', 'd', 'o', '33', 'a', 'o', '3167', 'c', '2359', 'r', 'm', '6865', '7797', '5473', '8905', 'j', '9319', 'u', 'y', 'a', '3117', '7789', '9837', '6887', '317']
A:
a, c, d, j, m, o, r, u, y