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:
['t', 'h', '6141', 'g', 'f', 'z', 'n', 'b', 'k', '9059', 'y', 'p', '4289', '2683', 'a', '3267', 'w', 'p', 't', '3623', '7759', 'a', 'o', 'm', '9815', 'q', 'u', '8051', '6871']

Ex Output:
a, b, f, g, h, k, m, n, o, p, q, t, u, w, y, z


Ex Input:
['c', '8389', 'j', '6113', '5843', 'f']

Ex Output:
c, f, j


Ex Input:
['i', 'a', 'a', '6489', '3441', 'e', '4743', '4471', 'd', '2011', 'c', 'c', 'p', '9071', 'e', 'h', 'm', 'x', '777', 'y', '5811', 'i', '9507', 'p']

Ex Output:

a, c, d, e, h, i, m, p, x, y