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:
['u', 'o', 'b', 'b', '5873', 'w', 'v', '4171', '7957', '3501', '2563', 'l', 'q']

Ex Output:
b, l, o, q, u, v, w


Ex Input:
['a', '7599', 'i', '9455', '3955', '2015', 'j', '7345', 'x', 't', 'c', '1317', '9155', '6383', '7793', 'n', '5581', 'v', '3485', 'n', 'r']

Ex Output:
a, c, i, j, n, r, t, v, x


Ex Input:
['h', '6295', 'z', '9505', '7809', '5423', '8789', '867', '8003', '8427', 'x', 't', '2189', 'e', 'h', 'n', 'o', '5641', 'j', '7045', '4631', '9099']

Ex Output:

e, h, j, n, o, t, x, z