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]: ['r', 'n', '7583', '8697', '7927', 'l', '5003', '1363', 'p', 'e', 'q', '6227', '6915', '8619', '9011', 'n', '3063', '3799']
[EX A]: e, l, n, p, q, r

[EX Q]: ['231', 'r', '5673', 'j', '589', 'z', '4659', 'a', '3763']
[EX A]: a, j, r, z

[EX Q]: ['q', 'y', 'w', 'e', '6775', '2105', 'o', 'm', 'm', 'w', '7947', '1089', 'c', '2717', 'v', '2391', '9201', 't', 'k', 'e', '2403', '9923', 'o', 'r', '1385', '143', '5141', '3599', 'j', '7399', 'p', '1919', '7271', '2385', '8511', '919', 'b', '7829', '8177', '5049', 'g']
[EX A]:
b, c, e, g, j, k, m, o, p, q, r, t, v, w, y