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:
['4927', 'h', 'x', '4719', 'j', 'f', '7797', 'l', 'i', 'q', 'x', 'i', 'k', '3215', 'k', '1625', 'g', 't', 'i', 'w', 'n', '6659', '8355', '831', 'h', '9723']

Ex Output:
f, g, h, i, j, k, l, n, q, t, w, x


Ex Input:
['u', 'i', '1185', '3795', '5417', 'k', 'b', '2629', '2635', 'z']

Ex Output:
b, i, k, u, z


Ex Input:
['n', 'c', 'n', 's', 's', 'x', '2727', '5247', '4323', '2559', 'q', '7461', '5117', '9699', 'z', 'd', '1271', 'x', 's', '693', 'u', '8763', 'e', '7979', '4993', '9483', 'i', '7841', 'o', '1019', '681']

Ex Output:

c, d, e, i, n, o, q, s, u, x, z