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:
['6143', 'y', '5505', '9813', 'r', 'v', 'u', '8681', '2387', 'u', 'o', 'm', '9793', 'm']

Ex Output:
m, o, r, u, v, y


Ex Input:
['2381', 'y', '6631', '5839', 'r', 'm', 'z', 'b', '4663', '595', '7771', '5305', '5087', '3317', '3125', '9551', '4343', '5121', 'm', 'i', '131', '8401', '5379', '1775', 'u', '1125', '9793', '4123', 'h', '1613']

Ex Output:
b, h, i, m, r, u, y, z


Ex Input:
['g', 'd', '3539', '2487', '9523', '3067', 'f', '4863', 'q', 'n', '9863', '1643', '9285', 'n', 'q', 'g', '1841', '8307', 'b', '391', 's', 's', 'j']

Ex Output:

b, d, f, g, j, n, q, s