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]: ['6643', '6757', 'h', '1033', 's', 'c', '2003', 'p', '5483', 'f']
[EX A]: c, f, h, p, s

[EX Q]: ['w', '9437', 's', '9819', 'q', 'q', '4443', 'p', '377', '6777', 's', 'x', 'a', 'o', '9205', '9289', '7103', 'k', 'l', '9453', '9043', 'k', 'r', 'g']
[EX A]: a, g, k, l, o, p, q, r, s, w, x

[EX Q]: ['u', '7801', '359', 'x', '9267', '359', '2241', '3935', 'n', '835', '1567', '4307', '9625', '4255', '8875', 't', 'q', 'f', '9595', '2607', '1141', 't', '9297']
[EX A]:
f, n, q, t, u, x