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]: ['4041', 'l', 'g', '9571', '9295', '1395', 'l', 'p', 'f', 'w', 'g', '1721', '2421', 'w', 'z', '2235', 'p', '7851']
[A]: f, g, l, p, w, z


[Q]: ['9113', '3625', 'u', '8189', '3649', '259', '5539', '1583', 'g', '4037', 'y', 'v', '8337', 'd', 'q', 'j', 'c', 'h', 'p', '1601', 'z', 'c', 'n', '1767', '1679', '1805', 'm', '4469', '2487', '6015', '973']
[A]: c, d, g, h, j, m, n, p, q, u, v, y, z


[Q]: ['s', '7805', 'p', '8551', '4749', 'a', '9073', '6639', '5089', '8821', '6481', 'i', '3239', '1873', 'b', 's', '4037', '6637', 'x']
[A]:
a, b, i, p, s, x