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]: ['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']
[EX A]: b, d, f, g, h, i, k, l, p, r, t, u, w, x, y, z

[EX Q]: ['a', '7599', 'i', '9455', '3955', '2015', 'j', '7345', 'x', 't', 'c', '1317', '9155', '6383', '7793', 'n', '5581', 'v', '3485', 'n', 'r']
[EX A]: a, c, i, j, n, r, t, v, x

[EX Q]: ['4671', '1637', 't', 'n', '1965', '3027', 'm', 'b', '4139', '8491', 'w', '2481', 'b', '7549', 'b', 's', '8063', '233', 'f', 'n', '349', '4581', '7735', '2427', '9275', '3825', '5231', 'n', 'o', '5805', 'a', 'a', 'h', '7921', 't', 'h', '5199']
[EX A]:
a, b, f, h, m, n, o, s, t, w