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', 'v', 'w', '7939', '571', '395', '3707', 'm', 'd', 'u', 'o', 'r', '4211', '9645', '8731', '2441', 'y', '8147', '8809', 'e', 'b', '6835', 'i', '2083', 't', '3481', 'f', 'f', '5559', '3601', 'e', '5637', '5185', 't', '6777', '3419', '8637', 'p', 's', 'o', 'x']
[EX A]: b, d, e, f, i, m, o, p, r, s, t, u, v, w, x, y

[EX Q]: ['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']
[EX A]: a, c, e, g, j, l, n, q, s, x

[EX Q]: ['5867', 'a', '9439', '7835', 'y', 'k', '6219', '4271', '9513', 'n', 'm', '3527', 'l', 'o', '7271', 's', '3437', 'f', 'z', '1421']
[EX A]:
a, f, k, l, m, n, o, s, y, z