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.

['i', 's']
i, s

['5463', '5683', 'w', '4071', '3997', 'i', '9677', 'q', 'l', 'v', 'w', '5325', '197', 'g', 'g', '3227', '3477']
g, i, l, q, v, w

['t', 'j', '4705', '7919', '3573', '8905', '4175', '1067', 'v', '1699', '6951', '765', '6513', '2633', 'a', '7565', 'k', 'v', '6277', 'i', 'c', 'v', '5989', 'j', 's', 'q', '67', 'e', '4061', 'i', '2481', '8595', '3297', 't', '4851', '2121', 'b', '4957', 'g', '7659', '113']

a, b, c, e, g, i, j, k, q, s, t, v