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.

['i', 'x', 'n', 'w', '8915', 'd', 'd', 'd', '6025', '7861']
d, i, n, w, x

['l', '6313', '3199', 'w', '249', '8747', '7391', '3871', '173', 'x', 'o', '8647', '4413', '3645', '6123', '701', 'q', '2147', '4289', '7333', '533']
l, o, q, w, x

['3459', '1501', 'x', '5419', '6987', '6271', '7677', 'u', 'q', 'x', 'q', 'd', '9689', 'm', '6689', 'i', '805', '8727', '3417', 'i', '3069', 'e', '2661', '1637', 'v', 'z', 'p', '6819', 'a', 'v', '4521', 'r', 'q']

a, d, e, i, m, p, q, r, u, v, x, z