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:
['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:
['4653', 'e', 'c', 'j', '6739', '3963', 'q', '4649', 'v', 's', 'j', '9757', '8075', '6253', '4365', 's', '9101', 'd', '6989', 't', '5687', '7389', '139', '4029', '5073', 'q', 'e', '2455', '1075', 'j', '1329', 'l', '4689', 't', 'z', '4179', 's', 'l', 'w', 'n', '6569', '8907', 'v', '605', 'y']

Ex Output:
c, d, e, j, l, n, q, s, t, v, w, y, z


Ex Input:
['2403', 'p', 'b', 'n', '5083', 'r', 'b', '589', '5947', 'm', 'k', '2111', '5659', 'v', 'v', '2013', 'o']

Ex Output:

b, k, m, n, o, p, r, v