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]: ['t', 'r', '2959', '2517', 'a', '9959', '729', '511', 'y', 'r', '465', 'c', '687', 'm', 'b', 'm', '3449', '9713', 'g', '8275', '8823', 'a', 'z', 'w', '2185', '6283', '8457', '8137', '7163', '8329']
[EX A]: a, b, c, g, m, r, t, w, y, z

[EX Q]: ['o', '4167', 'b', '1651', '8327', '9219', 'o', 'v', '5841', '6057', 'i', 'q', 'o', 'r', 'a', '7069', 'y', 'h', 'd', '3775', 'j', 't', '3663', '55', '7117', 'e', 'u', 'm', '931', '5777', '8773', '4891']
[EX A]: a, b, d, e, h, i, j, m, o, q, r, t, u, v, y

[EX Q]: ['r', '9277', 'a', '7091', 'x', 't', 's', '2499', 'g', 'j', 'd', 'f', 'h', '1083', 's', 'd', 'c', 'l', 's', 's', 'n', '7883', '3275', '7069', '3851', 's', '1701', 'd', '8651', '5849', 'l', '6707', 'w', 'c', 'z', 'o', 'k']
[EX A]:
a, c, d, f, g, h, j, k, l, n, o, r, s, t, w, x, z