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.

['9579', 'm', 'v', 'r']
m, r, v

['7591', '7521', 'm', '1429', 'x']
m, x

['1885', '995', '8317', '7675', 'n', '3083', 'p', 'h', 'l', '4099', '3235', '5029', 'b', '2195', 's', 'e', 'p', 'w', 'x', '859', 'd', '9279', '2313', '5519', '3481', '1065', '5471', '3551', '2119', 't', '489', '8561', '3195', 'o', 'j', '7791', '3463', '3995', 'e', '3883', 'l']

b, d, e, h, j, l, n, o, p, s, t, w, x

