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:
['b', 'a', '7411', '4471', 'z', 'l', '2051', 'q', '6749', '8647', 's', 'y', 'h', '9319', 'e', '5419', 'y', 'q']

Ex Output:
a, b, e, h, l, q, s, y, z


Ex Input:
['k', 'n']

Ex Output:
k, n


Ex Input:
['7783', 'c', 't', 'v', '4441', 'm', 'o', 'f', '6327', '6987', 'j', '3975', 'o', 'y', '9225', 't', 'p', 'd', 'o', '8721', '2617', '7437', '4027', 'v', 'p', 'o', '4611', '4725', 'a', '1305', '4559', 'e', '2327', 'w', '5439', 'n', '8329', '6473', 'y']

Ex Output:

a, c, d, e, f, j, m, n, o, p, t, v, w, y