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: ['57', 'j', 'n', '877', 'u', 'w', 'j', 'f', '8977', 'h', '469', '9417']

Output: f, h, j, n, u, w


Input: Consider Input: ['815', '6967', '6553', 'r', 'y', '3641', 'q', 'b', '6131', '4289', 'w', '6093', '6055', 'i', 'b', 'y', '5107', 'v', 'g', '9709', 'x', 'i']

Output: b, g, i, q, r, v, w, x, y


Input: Consider Input: ['k', '679', '7029', '3247', 't', 'f', 't', '8381', 'h', 'u', '2047', 'r', 'i']


Output: f, h, i, k, r, t, u