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 Q]: ['x', 'i', 'k', 'c', 'f', '3057', '481', '5887', '847', 'c', 'x', 't', 'g', '5805', 'a', 'i', '2885', '403', 'x', 'c', '4815', '2765', 'c', '5181', 'l', 'e', '3843', '1171', 'u', '7867', 'z', 'e', '9349', '5011', 'h', 'x', '3193', 'i', '4595', '8621', '6007', '1879']
[EX A]: a, c, e, f, g, h, i, k, l, t, u, x, z

[EX Q]: ['6209', 'x', 'j', 'w', '7965', '4905', '6297', '4291', '7183', 'a', 'l', '5267', 'r', '5935', 'a', '7865', 'h', 'p', '6117', 'a', 'y', 'y', 't', 'v', '7271', 'e', 'e', 'z', 'i', 'l', '4731', '2059', 'm', '5703', 'k', 'f', '8125', 'e', '7569', 'r', '2287', '593']
[EX A]: a, e, f, h, i, j, k, l, m, p, r, t, v, w, x, y, z

[EX Q]: ['355', '2377', '6109', '2315', '9689', 'p', '7097', '9291', '397', '6989', '4261', '9015', 'f', 't', '1685', '5579', 'l', 'd', '7877', 'w', '4713', '5337', '4119', '1863']
[EX A]:
d, f, l, p, t, w