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:
['h', '1797', '8211', 'n', 'r', '7707', '2063', '4655', 'x', '5521', '8327', 'g', '7659', 'i', 'x', 'w', '9465', '4625', 'q', '5377', 'r', '225', 'r', 'i', 'e', '4163', 'g', 'g', '3537', 's']

Ex Output:
e, g, h, i, n, q, r, s, w, x


Ex Input:
['2697', 's', '8733', 'n', '5871', 'f']

Ex Output:
f, n, s


Ex Input:
['u', '4873', '4731', 'o', 'a', 'l']

Ex Output:

a, l, o, u