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]: ['1429', '7763', '9737', 'l', '1865', 's', '9871', 'e', 'c', 'q', '2727', 'v', 'p', 'd', 'p', '6771', 'c', '7051', 'e', 'b', 'd', 'o', '7427', 'x', 'e', 'm', 'u', '4887', '1649', 'u', 'h', '5249', 'e', '7579', '8549']
[EX A]: b, c, d, e, h, l, m, o, p, q, s, u, v, x

[EX Q]: ['f', '6817', 'f', 'd', '3835', '3051', 'u', 'l', '7679', 'b', '3931', '1441', 'q', '8675', 's', '5487', 'y', '2279', 'x', 'y', '9513', '2875', '1771', '879', '2927', '3469', 'v', 't', 'k', '9991', '2565', '7345', '973', 'w', 'i', '6105']
[EX A]: b, d, f, i, k, l, q, s, t, u, v, w, x, y

[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