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.
--------
Question: ['9783', '3185', '8225', 'u', '1123', 'd', '3453', 'i', '7713', '8457', '8609', 'h', '2767', 'e', '7191', '2929', '1089', '393', 'e', 'd', '11', '9329', '683', '1271']

Answer: d, e, h, i, u


Question: ['d', 'r', '7769', '2159', 's', '3269', '5527', 'l', 'z', 'e', '5165', 'x', 'x', '8273', 'g', 'm', '7609', '4015', '6403', '3753', 'y', 'h', 'l', 'i', '389', 'm', 'u', '6845', 'r', 'c', '7571', '3355', '9755', 'n', '4625', 'p', '5645', '1703', '4439', 't', '8431']

Answer: c, d, e, g, h, i, l, m, n, p, r, s, t, u, x, y, z


Question: ['k', '4241', '8031', '3241', 'w', 'h', '9679', 'n', 'o', 'r', 'v', '6437', '1665', 'k', '5531', '4201', '4549', 'n', 'i', '8451', '5345', '5651', '7739', '2409', 'v', 't', 'a', 'i', 'u', '3609', '209', 'm', 'd', 't', 'h', '2717', 'y', '6391']

Answer:
a, d, h, i, k, m, n, o, r, t, u, v, w, y