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.

Example Input: ['m', '7517', '9361', '9567', '8785', 'k', '5699', '3585', 'v', '1913', '1651', 'g', 'p', '2731', 'q', 'h', '467', 'r', '1091', '9801', 'a', '6645']
Example Output: a, g, h, k, m, p, q, r, v

Example Input: ['9117', '1153', 'f', 'b', '9979']
Example Output: b, f

Example Input: ['7747', 'l', '5007', '3101', '6033', 'd', 'b', 'p', 'r', '3509', 'w', 'e', 's', 'a', 'o', 'w', '8435', '913', '2347', '9565', 'c', '3439', 'j', '2657', 'b', 'f', 'f', '7945', '4673', 'w', 'e', '2947', '5515', '7453', 'j', 'c', 's', 'l', 'n', '9225', '2769', 'u', '1273', 'x']
Example Output:
a, b, c, d, e, f, j, l, n, o, p, r, s, u, w, x