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]: ['8859', '575', 'l', 'e', '6575', '1303', '8643', '1395', '3171']
[EX A]: e, l

[EX Q]: ['4031', 't', 'o', 'c', 'x', '3007', '8329', '6345', '1267', '1017', 'o', 'x', 'l', '4129', 'd', '1987', '487', 'o', 'g', 'j', 'v', 'x', '3983', 'f', 'g', '5759', 'k', 'i', 'o', 'b', 'n', '683', 'j', 'o', 't', '4361', 'u']
[EX A]: b, c, d, f, g, i, j, k, l, n, o, t, u, v, x

[EX Q]: ['t', 'i', 'n', '6517', 'l', 's', '2093', 'z', '5959', '5683', '4365', 'd', '7743', '8039', 'j', 'g', '4617', 's', 'd', 't', '4367', '7197', '1257', 'e', '4067', '7723', 'e', 't', '4231', '8879', '433', 'i', '1311', '5503']
[EX A]:
d, e, g, i, j, l, n, s, t, z