Instructions: 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: ['b', '4651', '7823', 'y', '4525', '7675', '9485', 'w', '1951', '7099', 'x', 'x', 'g', '9065', '4369', '5329', '3057', '4169', '4897', '551', '7465', 'b', 'n', '5153', '2807', '3723', 'o', '2371', '9049', 'j']
Output:
b, g, j, n, o, w, x, y