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: ['w', 'g', '1649', 'a', '2115', '6763', 'r', 't', 'l', 's', 'y', '5659', 'a', 'b']

Output: a, b, g, l, r, s, t, w, y


Input: Consider Input: ['n', 'h', 'j', '5945', '8511', 'y', '7739', '4717', '2483', 'p', '9545', '7647', '9863', '5591', '5393', 'i', '9225', '589', '1497', 'j', 'm', '2397', 'a', 'd']

Output: a, d, h, i, j, m, n, p, y


Input: Consider Input: ['s', 'x', 'x', '8779', 'd', 'g', 'a', 'a', '1109', '573', 'o', '5537', 'y', 'q', 'm', 'i', '6769', 'g', '6097', '4711', 'a', 'h', '4053', '1633', 'o', '3267', 'u', '9621', 'n']


Output: a, d, g, h, i, m, n, o, q, s, u, x, y