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: ['815', '6967', '6553', 'r', 'y', '3641', 'q', 'b', '6131', '4289', 'w', '6093', '6055', 'i', 'b', 'y', '5107', 'v', 'g', '9709', 'x', 'i']

Output: b, g, i, q, r, v, w, x, y


Input: Consider Input: ['n', '7489', 'n', 'n', '9787', '7829', 'n', '3481', 'v', 'l', '8927', 'c', 'm', 'd']

Output: c, d, l, m, n, v


Input: Consider Input: ['5847', '999', '3119', '2887', 'c', '7711', '1773', 'y', '6301', '4603', '2391', '4659', '2049', '2301', '8245', 'v', 'o', '571', 'p', 'd', '2365', 'c', '1293', '6487', 'f', '8469', '4685', 'l', '6623', '3897', 'y']


Output: c, d, f, l, o, p, v, y