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: ['f', '9203', 'w', 'f', '3751', '8095', '1319', 'f', '3017', 'r', 'y', '8221', '2715', '9959']
Example Output: f, r, w, y

Example Input: ['d', '4377', '9271', '8053', '9519']
Example Output: d

Example Input: ['z', '3777', 'b', 'w', '1737', 'a', '1709', 't', '3233', '6431', 'b']
Example Output:
a, b, t, w, z