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: ['c', '7039', 'g', '1899', 'r', '507', 'c', '2587', '3865', '1729', '3927', 'r', '3535', '2791', 'm', 'l', 'r']
Example Output: c, g, l, m, r

Example Input: ['9013', 'e', 'm', 'p', 'k', '161', 'k']
Example Output: e, k, m, p

Example Input: ['697', 't', 'a', 'w', 'h', '1933', 'v', '8373', 'm', 'a', 'z', '7903', '1245', '8691', 'q', 'b', '9169', 'h', '5397', 'e', '4547']
Example Output:
a, b, e, h, m, q, t, v, w, z