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:
['2915', '6033', '5541', '4685', '1263', '6701', 's', '7269', 'g', '8033', '8171', '6917', 'l', '2913', '447', 'g', 'a', 'z', 'o', '7563', '5385', '5259', '5067', '4869', '2653', '6925', '7001', '8553', 'x', '1243', '9131', '5037']

Ex Output:
a, g, l, o, s, x, z


Ex Input:
['2741', '2541', '8943', 'l', '4047', '2211', 'p', 'e', 't', '7645', '9771', 'f', '5063', '2303', '6097', '5089', 'd', 'e', '1409', '3125', '2171', 'g', '1247', '4045', 'v', 'h', 'u', '2587', '5207', '5553', 'g', 'd', '6891', 'e', '2471', '2435']

Ex Output:
d, e, f, g, h, l, p, t, u, v


Ex Input:
['7467', 'b', 'k', 'o', 'c', '4901', 'x', '8869', '1821', 'x', 'v', '85', 'z', '1059', 'q', 'z', '3059', '37', '8045', '4661', '1011', 'd', '8551', '337', '529', '1551', '637', '8599', '7057', '8351', '6837', '3777', 'y', 'a', '1393', '823', 'q', 's', 'p', 'e', 'y', 'h', 't', 'c', '9819']

Ex Output:

a, b, c, d, e, h, k, o, p, q, s, t, v, x, y, z