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: ['7997', 'm']
Example Output: m

Example Input: ['c', '8389', 'j', '6113', '5843', 'f']
Example Output: c, f, j

Example Input: ['7761', 'h', 'k', 't', 'k', '4607', 'g', '6497', 'w', '9189', 'l', 'v', '9433', '8129', '491', 'w', 'u', '6325', 'k', 'g', '9933', '6989', 'l', '8929']
Example Output:
g, h, k, l, t, u, v, w