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.

[Q]: ['a', '7599', 'i', '9455', '3955', '2015', 'j', '7345', 'x', 't', 'c', '1317', '9155', '6383', '7793', 'n', '5581', 'v', '3485', 'n', 'r']
[A]: a, c, i, j, n, r, t, v, x


[Q]: ['7155', 'y', '145', '7147', 'u', '8453', 'd', '3693', '6471', '5289', 'n', 'p', '8289', '2929', '199', 'e', '8377', '8937', '5315', 't', 'l', '7715', 'c', 'y', 'f', '9999', 'p', '3655', '5489', 'q', '2321', '9881', '2265', 'n', 'v', '455']
[A]: c, d, e, f, l, n, p, q, t, u, v, y


[Q]: ['7971', '8785', 'h', '415', '6043', '2943', 'q', 's', '2449', 'i', '8461', '1763', '8477', '4285', '1483', '1801', '313', 'd']
[A]:
d, h, i, q, s