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:
['u', 'd', '4193', '5687', 'p', 'r', '7787', 't']

Ex Output:
d, p, r, t, u


Ex Input:
['5611', 'x', 't', 'p', '5711', '7079', '5251', '429', 'z', 'u', '8721', '9321', '79', 'i', '189', '3605', 'k', '445', 'r', 'k', 'o', '2189', '8521', '8849', '2651', 'm', '4149', '1577', '3085', '5275', '6413', '5265', '6089', 'r', 'f', '5013']

Ex Output:
f, i, k, m, o, p, r, t, u, x, z


Ex Input:
['j', 'x', 'm', '9613', '665', 'l', 'x', '1513', 'y', 'w', '7515', 'm', '8301', '8849', 'b', '9991', '4547', '483', '7681', 'w', 't', 'r', '5413', 'u', '2537', 'm', 'a', '4073', '5559', 'a', 'k', '4701', 'k', '1199', '9273', '6529', '7065', 'j', 'z', 'l', '7013']

Ex Output:

a, b, j, k, l, m, r, t, u, w, x, y, z