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: ['j', 'y', '9907', 'a', '5715', 'l', '9817', '1949', '2697', '2255', '9571', '8957', '9329', '6055', 'z', 'q', '1185', '4593']

Output: a, j, l, q, y, z


Input: Consider Input: ['x', 'b', '1467', 'y', '2101', 'y', 'm', '2745', 'z', '429', '7523', 'e', 'f']

Output: b, e, f, m, x, y, z


Input: Consider Input: ['4731', '3599', 'd', '3515', '9283', 'p', 'a', 'd', 'u', '3773', '3801', 'l', '8241', 'v', '4667', '5557', 'n', 'w', '6319']


Output: a, d, l, n, p, u, v, w