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: ['d', '4377', '9271', '8053', '9519']
Example Output: d

Example Input: ['749', 'r', 'a', 's', 't', '5905', 'm', 'd', '8437', '4583']
Example Output: a, d, m, r, s, t

Example Input: ['7131', 'g', 'i', '2203', 'h']
Example Output:
g, h, i