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: ['4905', 'w', '3143', '2217', '573', '1073', '63', 'a', '3971', '2887', '3485', 'y', '3893', '1059', '7623', 'x', 'd', '2991', 'e', 's', '735', 'm', 's', '257', 'x', '5559', '97', 'p', '7237', '693', '7229', 'd', '2311', '807', 'd', 'l', '1247', 'l', '359']

Answer: a, d, e, l, m, p, s, w, x, y


Question: ['a', 'y', 'v', 'f', 'x', 'k', 'f', 'j', '6245', '6289', 'd', '6909', '8701', 'm', '3277', 'f', 'j', 'j', '9227', '8663', '5771', 'j', 'n', 'u', '7837', 's', '2539', '6363', 'g', 'a', '1009', 'v', '1483', 'x', 'i']

Answer: a, d, f, g, i, j, k, m, n, s, u, v, x, y


Question: ['5631', '2675', '9541', '9505', '1615', '6125', '8623', 'e', '3305', '4085', '291', 'm', '3119', 'f', '195', '9509', 'l', '9847', '9163', '4933', '4571', '8879', 'v']

Answer:
e, f, l, m, v