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:
['t', 'a', '2481', '2841', 'a', '2871', 'm', '4435', 'g', '8201', '4351', '9045', 'o']

Ex Output:
a, g, m, o, t


Ex Input:
['6463', '871', '5781', '283', '9653', 'f', '9661', '3365', '2889', '5499']

Ex Output:
f


Ex Input:
['6143', '9073', 'h', '1459', 'q', '5799', '6555', '525', '7921', '5041', '3273', '383', 'd', '9075']

Ex Output:

d, h, q