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]: ['6737', 'g', '9985', '5257', 'k', 't', '7863', 'y', '8319', 'l', 'o', '6505', '6531', 'z', '3055', '2943', '3625', 'h', '4867']
[A]: g, h, k, l, o, t, y, z


[Q]: ['c', 'e', '6509', '1295', 'u', '5445', '1731', '3049']
[A]: c, e, u


[Q]: ['2481', 't', 'e', 't', '3767', 'w', 'f', '919', '2507', 's', 'r', 'd', '5813', '1499', 'a', '3447', '5953', 'b', 'h', '5627', 'j', '9857', '3085', 'w', '7519', 'z', 'z', '7793', '8663', 'k', 'q', '7149', '1185', 'l', '7691', '7525', 'e', 'r', 'o', 'f', '8705', '5859', '3845', 'q', '6365']
[A]:
a, b, d, e, f, h, j, k, l, o, q, r, s, t, w, z