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]: ['57', 'j', 'n', '877', 'u', 'w', 'j', 'f', '8977', 'h', '469', '9417']
[EX A]: f, h, j, n, u, w

[EX Q]: ['2161', '8009', '3057', 'r', '3897', 'd', 'j', '2727', 'b', '3231', 'i', '9227', '393', '5799']
[EX A]: b, d, i, j, r

[EX Q]: ['b', '3289', 'y', 'v', 'm', 'y', 'r', '1851', 'o', 'm', '7569', 'h', '4393', '6001', '7223', '4433', 'b', 'm', '9763', '1725', 'n', 'r', '109', 't', 'm', 'f', 'p', '7481', '9101', '201', 'g', '8287', 'd', '3839', 'r', '6745', 'i', 'e', '3189']
[EX A]:
b, d, e, f, g, h, i, m, n, o, p, r, t, v, y