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:
['s', 's', '6581', 'e', '7355', '1315']

Ex Output:
e, s


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:
['w', 'e', 'l', '4631', '9987', 'w', '5789', '5175', 'v', '1151', '5335', '4439', 'a', '9101', '4443', 's', '6837', '9675', '7011', 'q', 'c', 'm']

Ex Output:

a, c, e, l, m, q, s, v, w