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:
['6575', '2057', '2135', '6259', '7741', '4919', '7461', 'v', '401', 'h', 'u', '2391', '2181', 'y', '9273', 'd', 'b', 's', '7993', '9323', 'b', '7015']

Ex Output:
b, d, h, s, u, v, y


Ex Input:
['7123', 'm', 'h', '4065', 'c', 'n', '187', '3899', 'r', 'k', '2071', '9481', '6277']

Ex Output:
c, h, k, m, n, r


Ex Input:
['v', 'w', 'y', 'o', 'h', '3787', 'g', 'q', 'r', 'm', '5895', '4825', '143', '4039', '3779', 'n', '3281', '7109', '7997', '7081', 'y', '649', '6951', '5679', 'k', 'z', '8281', 'k', '19', '7415', 'c', '7337', 'q', 'm', 'l', '7811']

Ex Output:

c, g, h, k, l, m, n, o, q, r, v, w, y, z