Definition: 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: ['721', '663', 'q', '9441', 'o', '6201', '2715', '4727', '5387', 'f', '5595', 'j', '835', 'l', '9843', 'b', '4131', 'x', 'z', '5649', 'h', 'd', 'o', '4859', '7543', 'u', '2307', 'h', '9065', 'y', 'w', 'x', 'a', 'v', '6009', 'e', 'f', '351', '5271', 'm', '9027', '991', 'r']
Output:
a, b, d, e, f, h, j, l, m, o, q, r, u, v, w, x, y, z