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.

Q: ['l', 'i']

A: i, l
****
Q: ['7187', '7081', 'j', 'i', '3725', '6333', 'h', 'f', '6639', 'r', 'n', '3559', '2785']

A: f, h, i, j, n, r
****
Q: ['4863', 'f', '8727', '7017', 'x', 'l', '8271', '5031', '1999', 'd', '9809', 'a', '9093', '945', 'z', 'o', 'g', 'g', '5839', 'z', '8931', '457', '731', '9015', '4579', '7173', '2987', '3229', 'w', 'j', '303', '2899', 'c', 'v', '8469', '3127', 'h', '2469']

A:
a, c, d, f, g, h, j, l, o, v, w, x, z
****