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 Q]: ['o', 'l', 'm', 't', '4487', '1019', '9903', 'c']
[EX A]: c, l, m, o, t

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

[EX Q]: ['1797', 'i', 'c', '1063', 'f', 'q', '4965', 't', 'z']
[EX A]:
c, f, i, q, t, z