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.

Input: Consider Input: ['u', '8229', '2731', '6595', '4675', 'n', 'a', '7361', '7401', '7273', 'b', '279', '5539', '7919', 'j', 'x', '9521', '8837', '7391', 'h', 'x', 'h', '7283', 't', '3769', '2317', '9131', 'h', 'y', 'c', '1625', 'm', 'e', 'a', '8437', '7543', 'p', '2451', 'k', 'r']

Output: a, b, c, e, h, j, k, m, n, p, r, t, u, x, y


Input: Consider Input: ['6643', '6757', 'h', '1033', 's', 'c', '2003', 'p', '5483', 'f']

Output: c, f, h, p, s


Input: Consider Input: ['4009', 'y', '9077', 'p', 'q', '6711', '6443', '5491']


Output: p, q, y