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:
['7123', 'm', 'h', '4065', 'c', 'n', '187', '3899', 'r', 'k', '2071', '9481', '6277']

Ex Output:
c, h, k, m, n, r


Ex Input:
['4925', '9943', '7935', '4387', '2449', '5797', 'i', '1517', 'w', 'e', '9525', 'y', 't', 'e', '2793', 'v', '9897', '8709', '7247', 'o', 'f', '5549', 'q']

Ex Output:
e, f, i, o, q, t, v, w, y


Ex Input:
['f', 'e', 'k', 'a', 'p']

Ex Output:

a, e, f, k, p