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:
['s', 'w', '8949', '4025']

Ex Output:
s, w


Ex Input:
['135', 'u', '3435', '2985', '9811', 'y', '4309', '9757', '905', 'd', 'g', 'q', '1457', 'l', 'o', 'u', '4517', '2333', '3327', '577', 'a', '4041', '8101', '6211', 'f', 'j', '1721', '7217', 'q', '7443', '8477', '3117', '7779', '9339', '8615', 'm', 'c', 'f', 'c', '8979', '7895', 'k', 'w', '1619']

Ex Output:
a, c, d, f, g, j, k, l, m, o, q, u, w, y


Ex Input:
['j', '3913', '5535', 'j', '9389', 'z', 'o', 'v', 'z', 'g', 'h', 'g', 'h', 'g', '8173', 'x', '7713', 'z', 'h', '5507', '8933', '9913', '2295', '29', '7133', 'd', 'k', 's', '4853', '2177', 's', 'n', '4535', 's', 'v', 'o', 'v']

Ex Output:

d, g, h, j, k, n, o, s, v, x, z