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.

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

['j', '6675', 'u', 's', '705', '8227', 'f', 'w', 'n']
f, j, n, s, u, w

['e', 'n', 't', 'j', 'm', '7613', '3983', 'i', '7285', 'b', 't', '2639', 'u', 'n', '669', '575', '8621', 'p', 'm', 'i', '4229', '1593']

b, e, i, j, m, n, p, t, u