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]: ['6709', 't', 'n', 'k', '991', 'a', '8899', '3563', '527', 'm', '4599', '6679', 'm', 'x', 'f', 'o', '3275', 'x', '677', 'b', '3329', '3593', '5183', '5753', 'u', '6045', '2607', 'y', '9873']
[EX A]: a, b, f, k, m, n, o, t, u, x, y

[EX Q]: ['8739', 'v', 'm', '6277', 'l', 's', '109', '8057', '3835', 'd', 'u', 'f', 'w', 'd', 'p', '7705', '3643', '4455', 'u', 'p', 'u', '9407', 'g', 'w', '595', 'z', '6827', '6879', 'w', 'w', '6973', 'm', 'e', '1553', 'v', '3529', '8953', '3903', '5713', '8249', 'e', '1113', 'b', 't', 'r']
[EX A]: b, d, e, f, g, l, m, p, r, s, t, u, v, w, z

[EX Q]: ['691', '4087', 'w', 'j', '5235', 'j', 't', '8431', 'p', 't', 'h', '6465', '1303', '7387', 'a', '2931', 't', '9387', '9469', '6159', '9067', 'w', '3347', 'k', 'e', '8797', '2731', '3643', 'n', '3025', '3517', '4017', 'm', 'f', '2901', 'q', 'l', 'a']
[EX A]:
a, e, f, h, j, k, l, m, n, p, q, t, w