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: ['d', '771', '4193', 'e', '1537', 'a', 'q']

Output: a, d, e, q


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

Output: a, p, t, u, x, z


Input: Consider Input: ['j', 'g', 'h', 'q', '5687', 'v', '4771', '9687', 'y']


Output: g, h, j, q, v, y