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.

Ex Input:
['6411', 'x', 'i', '267', 'z', 'e', '5483', '8033', '3697', 'z', '4167', 'e', 'f', '7229', 'i', 't', '2197', 'g']

Ex Output:
e, f, g, i, t, x, z


Ex Input:
['s', 's', '6581', 'e', '7355', '1315']

Ex Output:
e, s


Ex Input:
['q', '6621', 'm', '5945', 'q', '899', '9049', 'z', 'j', 'r', 'v', 'l', '6949', '9247', '2419', '5423', '2397', '3943', 'p']

Ex Output:

j, l, m, p, q, r, v, z