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:
['5011', 'l', '925', 'e', 'b', '3077', 'm', '4541', '781']

Ex Output:
b, e, l, m


Ex Input:
['l', 'g', 'd', 'p', '8163', '6643', 'o', 'p', 'm']

Ex Output:
d, g, l, m, o, p


Ex Input:
['o', '5841', 'a', '3457', '3203', '1877', 'e', 'f', '9183', '1045', '3053', '9703', 'z', 'y', '6795', 'o', 'x', 'b', 'y', '969', 't', 'd', 'o', '1845', '5489', '7581', '1685', '4447', 'g', '587', '4359', '4901', 'l', '707', 'c', 'n', 'v', '4361', '5753', 'h']

Ex Output:

a, b, c, d, e, f, g, h, l, n, o, t, v, x, y, z