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.

['2799', '7519', '345', 'e', 'l', '9369', '4703', '4111']
e, l

['8975', '7199']
-1

['369', '5411', '3011', '7961', 's', '6623', 'q', 'x', '259', '5711', '5667', '2749', 'h', 'l', 'l', 'e', '1439', '8953', 'e', 'l', 'l']

e, h, l, q, s, x