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: ['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: ['m', 'z', 'd', '4667', 'v', '2881', '887', 's', '9861', 'd', '8821', '125', 't', '4493', '6749', '2983', '309', '6033', 'i', '3421', 'j', '4001']
Example Output: d, i, j, m, s, t, v, z

Example Input: ['i', '8137', '2949', '453', 'm', 't', 'z', '6819', '653', 's', '6135', '8171', '7399', 'z', '9027', 'q', '43', 'l', '9487', '2139', 'p', '3067', '6289', 'm', '979', '815', 'a', '5853', 't', 'p', '9099', 'f']
Example Output:
a, f, i, l, m, p, q, s, t, z