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]: ['7823', '2933', 'k', '4139', '5585', 'f', 'c', 'm', '2035', 'q', 'z', 'l', '1999', 'q', 'p', '7291', '2091', 'v', '423', 'e', 's', '6089', '4763', '6739']
[EX A]: c, e, f, k, l, m, p, q, s, v, z

[EX Q]: ['5011', 'l', '925', 'e', 'b', '3077', 'm', '4541', '781']
[EX A]: b, e, l, m

[EX Q]: ['6905', 'z', '4237', '1875', '2285', 'o', 'd', 'u', '9027', 'x', 'a', '7747']
[EX A]:
a, d, o, u, x, z