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: ['n', '7489', 'n', 'n', '9787', '7829', 'n', '3481', 'v', 'l', '8927', 'c', 'm', 'd']

Output: c, d, l, m, n, v


Input: Consider Input: ['2293', 'p', '9787', '7241', '8689', 'u', '3141', 'h', 'c', 'b', 'f', 's', '319', 'c', 'p', '6909', 'p', 'f', '1717', 'd', '2285', 's']

Output: b, c, d, f, h, p, s, u


Input: Consider Input: ['e', 'y', 's', '3755', '9429', 'e', '8217', 'e', 'w', '7781', 'i', 'i', '4401', 'e', '9863', '4351', 'g', 'a', '7191', '4181', '3405', '2637']


Output: a, e, g, i, s, w, y