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: ['815', '6967', '6553', 'r', 'y', '3641', 'q', 'b', '6131', '4289', 'w', '6093', '6055', 'i', 'b', 'y', '5107', 'v', 'g', '9709', 'x', 'i']
Example Output: b, g, i, q, r, v, w, x, y

Example Input: ['1985', '729', '169', '1299', 'l', 'z', '6809', '3083', 'w', 'f', '1989', 'z', '889', 'x', 'r', '1601']
Example Output: f, l, r, w, x, z

Example Input: ['k', 'd', 'h', 'u', 'm', 'o', '585', '6863', '7315', '7071', 'i', '5927', 't', '9791', '1509', '9939', 'f', '509', 'e', 't', '3847', '3579', '3793', '3643', 's', '4767', 'e', 'x', 'z', '8785', 'c', '9615']
Example Output:
c, d, e, f, h, i, k, m, o, s, t, u, x, z