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:
['v', 'l', 'v', '7673', '8975', 'u', '2471', '4151', '3615', '1139', 'i', 'z', '8833', 'v', '341', 'l', 'n', 'l', 'd', '9207', '1861', '3901', 'a']

Ex Output:
a, d, i, l, n, u, v, z


Ex Input:
['p', '2923', 'e', 'k', '5433', '605', '5079', 'k', 'p', 'x', '4845', '4099', '6795']

Ex Output:
e, k, p, x


Ex Input:
['a', '1039', '7987', 'z', '8425', '4727', '8399', '3391', 'n', '4907', '8343', 'i', '3445', '9797', '1117', 'e', '865', '7007', 'j', 'a', 'n', '7205', '2487', 'k', 'm', 't', 'q']

Ex Output:

a, e, i, j, k, m, n, q, t, z