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]: ['w', '1367', '5389', '9515']
[EX A]: w

[EX Q]: ['o', 'm', '8015', '787', '4787', '1727', 'f', 'e', 'c']
[EX A]: c, e, f, m, o

[EX Q]: ['6479', '2089', '9303', '8691', '4681', 'd', '5727', '1119', '4053', 'c', '2293', '1061', 'i', 'n', '3629', 's', 'g', 'l', 'k', '5375', '6603', 'j', 'm', 'h', '3659', 'o', 'm', '3595', 'q', 's', 'q', 'e', '1353', '1837', '4915', '2809', 'k', '8273', '4927', 'd', 'x', '3677', 'x', '2857']
[EX A]:
c, d, e, g, h, i, j, k, l, m, n, o, q, s, x