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: ['p', '2923', 'e', 'k', '5433', '605', '5079', 'k', 'p', 'x', '4845', '4099', '6795']

Output: e, k, p, x


Input: Consider Input: ['d', '4377', '9271', '8053', '9519']

Output: d


Input: Consider Input: ['4705', '6529', '1881', '6483', 'i', 'y', '8093', 'j', 's', 'v', 'p', '3063', 's', '9177', 'd', 'm', '1829']


Output: d, i, j, m, p, s, v, y