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.

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


[Q]: ['7065', 'q', 't', '3177', '9035', 'i', 'l', 'd', '8961', '1183', '6507', 'u', 'c', 't', '2467', '7659', 'e', '8963', 'j', 'g', 'p', '6779', '7115']
[A]: c, d, e, g, i, j, l, p, q, t, u


[Q]: ['9987', '3973', '6837', 'j', '3371', 'j', 'k', 'x', 'g', 'u', 's', '6861', '8353', '8705', '1041', 'y', 'q', '7499', '1585', 'w', '1889', '4671', 'p', '9417', 's', 'c', '6663', 'g', 'j', 'a', '7245', 'i', 'f', 'j', 'g', 'g', '1251']
[A]:
a, c, f, g, i, j, k, p, q, s, u, w, x, y