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]: ['4749', '4607', '625', '6907', 't', 'b', '8479', '6505', 'r']
[EX A]: b, r, t

[EX Q]: ['7839', '849', '5651', '4275', 'e', '5453', 'h', '2099', '485', 'i', 'm', 'n', '6563', '5675', '4001', 'h', 'm', 'z', '3467', '4237', '5035', '5609', '8475', '5171', 'v', '3883', '8461', '8611', '4853', 'd']
[EX A]: d, e, h, i, m, n, v, z

[EX Q]: ['7487', '751', '9381', 'q', '2799', 'j', '9925', 'f', 'x', '5181', 'a', 'y', 'p', '3855', 'y', 'u', '7777', '9315', '6659', '1825', 'l', '5091', 'l', 's', '7671', '3089', 'h', 'x', '515', '2523', 's', 's', 'e', 'q', '8845', 'n']
[EX A]:
a, e, f, h, j, l, n, p, q, s, u, x, y