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.

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

Output: a, b, g, l, r, s, t, w, y


Input: Consider Input: ['57', 'j', 'n', '877', 'u', 'w', 'j', 'f', '8977', 'h', '469', '9417']

Output: f, h, j, n, u, w


Input: Consider Input: ['4269', '3229', 'f', 'e', '7165', '9767', '6041', '7495', '1147', 'y', 'h', '5595', '6133', 'f', '8933', '2449', '6807', '823', 't']


Output: e, f, h, t, y