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]: ['8859', '575', 'l', 'e', '6575', '1303', '8643', '1395', '3171']
[EX A]: e, l

[EX Q]: ['5039', '2227', 't', 'o', '3313', 'm', 'v', '637', '6773', 'v', 'c', 'l', 'y', 'u', '3823', '9669', 'k', 'h', '3589', 'b', 'i', '3833', 's', 'm', '8201', 'u', '3143', 'k', '4111', '9769', '425', '4339', '209', 'c', 'c', '669', '8201', 'u', '7443', '2387', '6919', 'b', 'b', '2873']
[EX A]: b, c, h, i, k, l, m, o, s, t, u, v, y

[EX Q]: ['b', 'a', 'z', 'k', 'v', 'j', '8133', '4557', '4599', '1213', '2229', 'c', '6651', '5605', 'k', 'v', '581', 'i', '4641', '9227', 's', '979', '4071', 'g', 'u', 'u', 'j', '8245', 'i', 'g', 'i', 'o', 'y', '5131', '5633', '6749', 'g', 'x']
[EX A]:
a, b, c, g, i, j, k, o, s, u, v, x, y, z