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:
['o', 'm', '8015', '787', '4787', '1727', 'f', 'e', 'c']

Ex Output:
c, e, f, m, o


Ex Input:
['331', '125', 'u', 'a', 's', '6995', 'i', '3613', '9727', '7087', 'l', 'b', '8291', '813', 'i', '1169', '2159', 'd', '1451', 'q']

Ex Output:
a, b, d, i, l, q, s, u


Ex Input:
['p', 's', 'z', 'x', '9339', '2743', '6149', '4489', '7223', '8669', '1045', 'l', '5719', 'x', 's', 't', '4317', 'v', 's', '7093', '6509', '1495', '7053', '6731', 's', '4637', 'w']

Ex Output:

l, p, s, t, v, w, x, z