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:
['1799', '6409', '9257', '5923', 'm', 'j', '2565', '715']

Ex Output:
j, m


Ex Input:
['g', 'x', 'l', 'e', 'd', '1345', '1763', 'm', 'c', '2057', 's', 'a', '4127', 'y', 'h', '8581', 'o', '9203', '4761', 'd', 'u', 'n']

Ex Output:
a, c, d, e, g, h, l, m, n, o, s, u, x, y


Ex Input:
['n', 'j', '5923', 'y', '9047', 'm', 'i', 'c', '2779', 'd', 'm', 'd', 'h', '8961', 'd', 'w', 'm', 'v', '8957']

Ex Output:

c, d, h, i, j, m, n, v, w, y