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:
['3561', 'd', '9697', 'd', '7761', 'a', '2833', 'c', '2921', 't', '691', 'g', '4797', 'b', '3913', 'f', 'q', '7807', 'j', '3577', 'j', '1775', '2897', '2589', '993', '8595']

Ex Output:
a, b, c, d, f, g, j, q, t


Ex Input:
['i', '9215', 'n', 'p', '4815', '8757', 'm', '1755', 'c', 'z']

Ex Output:
c, i, m, n, p, z


Ex Input:
['127', 'x', '1475', 'c', '8991', 'a', '3741']

Ex Output:

a, c, x