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.

Ex Input:
['p', 'p', '7899', 'u', '971', '7289', 't', '5217', 'k', 'z', 'y', 'y', '6905', '9499', '4085', 'x', '955', 'v', 'j', '9049', '7927', '1757', '193', '2181']

Ex Output:
j, k, p, t, u, v, x, y, z


Ex Input:
['c', '7039', 'g', '1899', 'r', '507', 'c', '2587', '3865', '1729', '3927', 'r', '3535', '2791', 'm', 'l', 'r']

Ex Output:
c, g, l, m, r


Ex Input:
['4809', '3921', '4941', '3129', 'z', '6589', 'p', 'u', '6435', 'e', 'y', '3621', 'q', 'u', 'y', 'w', '2271', 'f', 'd', '9665', '7671', 'c', 'j', '8719', 'a', 'f', '1339', '659', '9039', 'y', '619', 'e', 'j', '255', 's']

Ex Output:

a, c, d, e, f, j, p, q, s, u, w, y, z