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: ['2349', 'p', 'a', '435', 'y', 'h', '3249', 'o']

Output: a, h, o, p, y


Input: Consider Input: ['u', '4731', 'l', 'p', '1997', '601', 'n', 'l', 'p', '211', '7355', '6537', 'w', 'x', '1741', '8145', '3689', 'm', 'y', '6945']

Output: l, m, n, p, u, w, x, y


Input: Consider Input: ['m', '2211', '6479', 'x', 'a', '9941', 'w', '5001']


Output: a, m, w, x