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:
['4123', '1397', '103', 'w', 't', 'j', '233', '7239', 'b', 'n', 't', '6273', 'l', '1167', '8389', '5609', '9029', '7741', 'o', 'p', '6547', '5593', 'd', '8401', 's', '4243', 's', 'u', 'm', '6659', '5691', '2105', '8897']

Ex Output:
b, d, j, l, m, n, o, p, s, t, u, w


Ex Input:
['491', '229', 'g', '6677', '4793', 'h', 'x', 'a', '2333', 'u', 'l', '785', 'p', '7331', '653', '5193', '5415', '8417', 'v']

Ex Output:
a, g, h, l, p, u, v, x


Ex Input:
['v', 'p', '6359', '8863', '5839', '1331', 'm', '9435', '1721', 'n', 'o', '243', 'b', '8377', '9281', '8103', 'b', '8893', 'w', '4463', 'b', 'f', 'p', 'r', 'k', 'b', 'k', 'q', '83', '2777', 'z', 'i', 'g']

Ex Output:

b, f, g, i, k, m, n, o, p, q, r, v, w, z