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.

Ex Input:
['7823', '2933', 'k', '4139', '5585', 'f', 'c', 'm', '2035', 'q', 'z', 'l', '1999', 'q', 'p', '7291', '2091', 'v', '423', 'e', 's', '6089', '4763', '6739']

Ex Output:
c, e, f, k, l, m, p, q, s, v, z


Ex Input:
['7917', '2295', 'q', 'v', '9373', 'w', 'n', 'q', '5803', 'g', 'k', 'm', '2167', 'k', '6425', 'x', 'g', '341', 't', 'u', '8829', 'h', '4333']

Ex Output:
g, h, k, m, n, q, t, u, v, w, x


Ex Input:
['157', '3041', '6429', 'g', '2569', '5943', 'a', 'g', 'h', 'o']

Ex Output:

a, g, h, o