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:
['c', 'a', 'p', 'p', '4203', '1587', '2953', '9809', '99', '5821', 't', 'i', '4213', '1809', 's', 'l', 'i', 'b', '9233', '3983', '7713', '1807', 'k', 'f', '7825', '5491', 'o', '1347', 'u', 'h', '3967', 'u', 'g', '6775', '1069', '9211', 'i', '3369', 'r']

Ex Output:
a, b, c, f, g, h, i, k, l, o, p, r, s, t, u


Ex Input:
['2527', '9123', '8717']

Ex Output:
-1


Ex Input:
['q', 'z', 'x', 'f', 'w', '9941', '5869', '6087', '7761', '503', '4491', 'e', 'e']

Ex Output:

e, f, q, w, x, z