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: ['u', '635', '5249', '9457', 's', '9317', '9407', 'l', 'w', '9705', 'k', '429', '5489', 'e', 'd', '2457', 'o', '4665', '1675', 'l', 'y', 's', 'o', 't', '4285']

A: d, e, k, l, o, s, t, u, w, y
****
Q: ['6597', '7889', 'x', 'v', 'm', 'j', 'j', 'w', 'v', '177', 'x', '8353', '5897']

A: j, m, v, w, x
****
Q: ['9275', '5115', 'd', 'n', 'y', 'y', '5763', 'v', '3593', '4521', '6073', 'c', '581', 'q', 'u', '2187']

A:
c, d, n, q, u, v, y
****