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:
['1985', '729', '169', '1299', 'l', 'z', '6809', '3083', 'w', 'f', '1989', 'z', '889', 'x', 'r', '1601']

Ex Output:
f, l, r, w, x, z


Ex Input:
['3821', '385', 'y', '8457', '6623', 'g', '5923', 'a', '7193', 'v', 'm', '8915', 'v', '5873', 'p', 't', 'w', 'y', '3617', 'h', 'w', 'j', '8047', 'u', '2271', 'v', 'a', '2181', 's', '1051', 'b', 'a', '9967', '987', 'z', '2255', '6349', '1249', '1397', 'q']

Ex Output:
a, b, g, h, j, m, p, q, s, t, u, v, w, y, z


Ex Input:
['6615', 'g', '9479', '9923', 'l', 'b', '7791', '8279', 'm', '4713', '5549', 'z', 'x', 'u', '7853', '3127', 'r', '4259', '5753', '2121', 'l', 'v', '3737', '6241', 'y', '1839', 'e', 'r', 'b', 'z', '9977', '6779', '3051', '2489', 'l', 'o', '8711', 'y', '9185', 'c', '9609']

Ex Output:

b, c, e, g, l, m, o, r, u, v, x, y, z