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.

['8281', '4831', '1329', 'g', 'e', '8879', 'n', 's', 'x', 'j', '6305', 'j', '921', '3677', '5107', 'n', 'j', '9285', 'a', '5329', '6671', 'c', '9283', 'l', 'a', '7907', 'q', '7605', '855', '6477']
a, c, e, g, j, l, n, q, s, x

['n', '7489', 'n', 'n', '9787', '7829', 'n', '3481', 'v', 'l', '8927', 'c', 'm', 'd']
c, d, l, m, n, v

['o', 'f', '149', '3691', '7851', 'n', 't', 'r', '6055', '5689', 'g', '1299', '2615', 'l', 'j', '4011', 'p', 'e', 'f', 'c', 'h', '2177', '7425', 't', 'r', 'x', 'c', 'j', 't', '183']

c, e, f, g, h, j, l, n, o, p, r, t, x