TASK DEFINITION: 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.
PROBLEM: ['x', 'o', '8161', 's', '3653', 'v', 'c', 'e', '5353', 'h', '9145', '333', 's', '7689', '8277', 'a', 'o', 'h', 'z', 'w', '9297', 'w', '9383', '8963', 'k', 'x', 's', 'w', 'h', 'j', '5737', 'o', '2247', '3723', '2043', '4615']

SOLUTION: a, c, e, h, j, k, o, s, v, w, x, z

PROBLEM: ['j', 'p', '8333', '8079', '4703', '7089', '8859', 'b', 'y', 'g', '7971', '6999', '2011', 'k', 'e', '9609', '4179', '3993', 'u', '3957', '6313', '4229', 'k', '5963', 'e', 'y', 'r', 'e', 'a', '2213', 'e', 'i', 'f', '7979', 'r', 'a', 'h', 'e', 'n']

SOLUTION: a, b, e, f, g, h, i, j, k, n, p, r, u, y

PROBLEM: ['5667', '417', '2455', '721', 'f', '5749', '5019', 'o', '5571', '303', '2511', '8383', '411', 'd', '3177', '365', 'i', 'x', 'u', '9697', '235', 'n', '2547', 'l', '4891', '5219', 'o', '9339', '7563']

SOLUTION:
d, f, i, l, n, o, u, x