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]: ['w', 'g', '1649', 'a', '2115', '6763', 'r', 't', 'l', 's', 'y', '5659', 'a', 'b']
[EX A]: a, b, g, l, r, s, t, w, y

[EX Q]: ['m', '6443', 'd', 'o', 'p', 'q', '3765', 'k', 'm', 'y', 'j', '3531', 'y', 't', '671', 'j', '3699', 'a', 'i', '1843', 't', 'd', '1205', 'k', 'h', '1209', '2913', '1301', 'k', 'd', '1769', '7985', 's', 'p', 'f', '4583']
[EX A]: a, d, f, h, i, j, k, m, o, p, q, s, t, y

[EX Q]: ['h', 'x', '1651', 't', '4247', 'e', 'v', '79', '7391', 'i', 'a', '911', 'e', '8527', 'f', '4633', 'q', '8241', 'j', 'p', '1511', '9679', '6255', 'l', 'g', '4501', '337', 'r', 'n', '2535', 'u', 'z', 'o', 'a', 'v', '905', 'e', '7801', '2769', '4089', 'c', '7265']
[EX A]:
a, c, e, f, g, h, i, j, l, n, o, p, q, r, t, u, v, x, z