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: ['2453', 'r', 'd', '8499', 't', 's', 'h', 'a', 'm', '9271', 'g', '2599', '6209', 'o', 'i', '4069', 't', '6793', '7679', '6643', '7359', 'm', 'f', 'w', '775', '3347', '6161', '9745', 'i']

Output: a, d, f, g, h, i, m, o, r, s, t, w


Input: Consider Input: ['7997', 'm']

Output: m


Input: Consider Input: ['6081', 'm', 'o', '4145', 'i', '8795']


Output: i, m, o