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.

['8235', 't', '1695', '9899', '3633', 't', '1823', 'r', 'x']
r, t, x

['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']
b, c, h, i, k, l, m, o, s, t, u, v, y

['s', '2225', 'v', 't', 'z', '8277', 'r', '6413', 'k', '4673', '145', 'e', '4233', 'z', 'v', '289', '2531', 'r', '1547', '8435', 'i', 'n', '8513', '9649', 'f', '6461', 'r', '5243', 'e', 'j', '1857', '2287', 'u', 'a', 'u', '8189', '6389', 'j', '7409', 'q']

a, e, f, i, j, k, n, q, r, s, t, u, v, z