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:
['r', 's', '3409', 'a', 'e', '6855', 'i', 'n', '8655', 's', 't', '8401', 'u', '9603', '8815', 'q', 'a', 'x', 'i', '8455', 'e', '5877', '3917', 'p']

Ex Output:
a, e, i, n, p, q, r, s, t, u, x


Ex Input:
['e', 'c', '4241', '2685', 'o', '9859', 'z', '2647', 'b', 'c', 'y', '1985', '5985', '5709', '6655', 'q', 'z', '9933', '6817', '6477', '1837', 'x', 'p', '9251', '3787', 'v', '5741', 'e', 'p', '493', '5949', '5519', 'v', 'g', '1403', 'z', 'h', 'z']

Ex Output:
b, c, e, g, h, o, p, q, v, x, y, z


Ex Input:
['9711', 'j', 'n', '5365', '9879', '2131', 'g', 'g', 'c', 't', 'a', 'x', 'n', 'o', 'd', 'o', 'o', '5615']

Ex Output:

a, c, d, g, j, n, o, t, x