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.

Example Input: ['s', 'c', 'e', '2457', '9413', 'r', '9949', 's', 'z', 'e', 'a', 'o', '7207']
Example Output: a, c, e, o, r, s, z

Example Input: ['6955', '721', '2763', '8121', '9109', '6341', 'p', 't', 'x', '6963', '1137', 'z', 'u', '1949', '7029', 't', '9539', 'a', 'u', '1873']
Example Output: a, p, t, u, x, z

Example Input: ['6157', '563', '1217', '5241', '4989', 'f', '6443', 'b', 'g', '9347', '6407', '2743', '977', '9097', 'h', 'u', '9163', 'e', 'v', '881', '2187', 'b', '9161', 'u', 'e', '3813', 'b', '5411', 's', 'o', 'i', 'c', '5483', '8071', 'v', '2981', 'n', 'x', 'a', 'j', '5709', 'n', '5335']
Example Output:
a, b, c, e, f, g, h, i, j, n, o, s, u, v, x