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.

[Q]: ['c', '1693', 'l', 'u', 'x', '3609', 'h', '4159']
[A]: c, h, l, u, x


[Q]: ['u', 'w', '401', 't', 'g', 'h', 'g', '8073', '9597', '1347', '7835', '5007', '977', 'p', '7679', 'b', '4883', '4931', '999', 'r', '1181', 'x', '2063', 'l', 'w', 'i', 'l', 'x', 'i', '9057', '5007', 'w', '743', '1635', 'y', 'f', '9227', 'z', '5227', 'd', '7129', 'k', '7657']
[A]: b, d, f, g, h, i, k, l, p, r, t, u, w, x, y, z


[Q]: ['h', '2681', 'h', 'p', 'p', '1897', 'o', 'b', 'e', '5927', 'x', 'n', 'v', 'o', 'r', 's', '8587', 'm', '9025', 'x', '8203', '5855', '9075', '7023', 'l', '5679', '8421', 'c', 'a', '2785', 'k', 'm']
[A]:
a, b, c, e, h, k, l, m, n, o, p, r, s, v, x