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:
['7065', 'q', 't', '3177', '9035', 'i', 'l', 'd', '8961', '1183', '6507', 'u', 'c', 't', '2467', '7659', 'e', '8963', 'j', 'g', 'p', '6779', '7115']

Ex Output:
c, d, e, g, i, j, l, p, q, t, u


Ex Input:
['8051', 'h', 'g', 's', 't', 'p', 'w', 'x', 's', '8521', 'm', '9719', 'j', 'n', 'i']

Ex Output:
g, h, i, j, m, n, p, s, t, w, x


Ex Input:
['9749', 'm', '2279', '1333', 's', 'f', 'e', '1149', '2535', 'a', '7333', 'g', '4823', 'c', '9499', '2221', '3737', '235', '6043', 'k']

Ex Output:

a, c, e, f, g, k, m, s