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.
--------
Question: ['o', '4167', 'b', '1651', '8327', '9219', 'o', 'v', '5841', '6057', 'i', 'q', 'o', 'r', 'a', '7069', 'y', 'h', 'd', '3775', 'j', 't', '3663', '55', '7117', 'e', 'u', 'm', '931', '5777', '8773', '4891']

Answer: a, b, d, e, h, i, j, m, o, q, r, t, u, v, y


Question: ['5463', '5683', 'w', '4071', '3997', 'i', '9677', 'q', 'l', 'v', 'w', '5325', '197', 'g', 'g', '3227', '3477']

Answer: g, i, l, q, v, w


Question: ['n', 'u', '5013', '3395', '3261', 'q', '5543', 'q', '7623', 'g', 'a', 'l', '5713', 'k', '3615', '1993', 'b', '2743', '889', 'w', '8925', 'q', '545', 'f', 'e', 'g', 'i', '5813', 'y', 'a', 'a', 'f', 'o', 'x', '7481', 'n', 'm', 'm', 'x', '167', '6587', '2347', '8013', 'p']

Answer:
a, b, e, f, g, i, k, l, m, n, o, p, q, u, w, x, y