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:
['4299', 'b', '4171', '7639', '6609', '927', '5249', 'o', 'p', '9851', 'e', '1311', '3777', '7799', '7687', '8809', 'c', 'r', '47', '1925', '1847', 'r', 'd', 'r', '1871', '5935', 'r', '2283', 'p', 'p', '2727', 'c', 'i', '7357', 'y', '5103', '6115', 'q', 'w', 'u', '9201', '4221', '7717', 'o']

Ex Output:
b, c, d, e, i, o, p, q, r, u, w, y


Ex Input:
['j', 'f', '9567', 'f', '7383', 'k', '599', '1091', '1501', 'y', 'o', 'c']

Ex Output:
c, f, j, k, o, y


Ex Input:
['d', '1123', 'r', 'l', '9641', 't', 'd', '4995', 'x', 'q', '5351', '6473', 'r', '1707', 'g', 'g', '6349', '4689', '7139', 'y', 'u', '6905', '1013', '1145', '5809', 'j', 'v']

Ex Output:

d, g, j, l, q, r, t, u, v, x, y