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.
--------
Question: ['v', '3765', '4065', 'a', '4201', 'f', 'x', '9275', 'q', '9303']

Answer: a, f, q, v, x


Question: ['g', '4165', 'n', 'w', 'n', 'e']

Answer: e, g, n, w


Question: ['n', 'b', 'j', 'r', 's', 't', 's', '127', '7023', 'h', 'o', 'm', 'h', 'u', '189']

Answer:
b, h, j, m, n, o, r, s, t, u