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.

['p', 'k', 'i', '753', 'u', 'm', '3817', '1597', 'l', 'm', 'a', 'i', 'b', 's', 'c', '2561', 'x', '5363', '1173', '8657', '2033', 'b', 'p', '3093', 'k', '6535', '307', '9925', 'b', 'q', 'q']
a, b, c, i, k, l, m, p, q, s, u, x

['7777', '6223', 'k', 'k', 'd', '9743', '189', '7705', 'c', '6115', '4275']
c, d, k

['i', '8559', '317', 's', '771', 'q', '8607', '4313', '155', '3365', '8129', 's', 'j', 'c', '1621', '8925', 'w', '6191', 'e', 't']

c, e, i, j, q, s, t, w