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:
['5761', '2289', '577', 't', '125', 'i', 'g', '9693', '747', 'd', '4829', '9587', 'f', 'k', 'w', 'v', '8607']

Ex Output:
d, f, g, i, k, t, v, w


Ex Input:
['4925', 'i', 'q', 'k', '7615', 'r', '7217', 'o', '8097', '9151']

Ex Output:
i, k, o, q, r


Ex Input:
['u', '9063', 'g', 'z', 'd', '3943', 'r', 'c', 'd', 'n', '9573', 's', 'w', '3417', '2911', '6765', 'g', '1979', 'q', '307', 'b', '5643', '1833', '8253', 'h', 't', 's', 's', '6993', '1871', 'p', '179', '7635', '4345', '8773', 's', 'v', '9803', '5947', 'e']

Ex Output:

b, c, d, e, g, h, n, p, q, r, s, t, u, v, w, z