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: ['d', '1625']

A: d
****
Q: ['g', 'p', '2925', 'n', 'o', 'y', '6381', 'l', '4963', 'g', 'm', 'u', 't', '9389', '3787', '7713', '1251', '779', 'i', 'w', '9869', 'y', 'y', '3881', 'k', 't']

A: g, i, k, l, m, n, o, p, t, u, w, y
****
Q: ['n', 'p', 'c', 'h', '9657', '3963', '4103', 'd', '8021', 'p', '6035', 'o', '571', 'r', 'g', 'q', 'f', 's', '421', '2931', '3509', '4481', '7681', '5005']

A:
c, d, f, g, h, n, o, p, q, r, s
****