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:
['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:
['9425', 'l', 'c', 'n', '5925', '2543', '3935', 'c', '7533', 'j', 'q', '3775', '5897', '9435', '69', 'e']

Ex Output:
c, e, j, l, n, q


Ex Input:
['9839', 'x', '363', 'j', '1847', 'g', '7479', 'n', 'h', 'x', '3461', '267', '7029', 'g']

Ex Output:

g, h, j, n, x