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: ['7417', '2597', '2633', '7721', 'v', 'l', 'p', '4389', 'l', '3965', '6279', 'm', 'v', 'o', 'd', 'o', 'h', 'd', 'r', 'e', '8993', '2711', 'o', 'q', '1399', 'i']

SOLUTION: d, e, h, i, l, m, o, p, q, r, v

PROBLEM: ['2453', 'r', 'd', '8499', 't', 's', 'h', 'a', 'm', '9271', 'g', '2599', '6209', 'o', 'i', '4069', 't', '6793', '7679', '6643', '7359', 'm', 'f', 'w', '775', '3347', '6161', '9745', 'i']

SOLUTION: a, d, f, g, h, i, m, o, r, s, t, w

PROBLEM: ['8315', 'o', 'm', '5087', '2735', '1135', 's', '859', '4007', '1891', 'o', 'u', '4101', '6137', '3911', '8377', 'a', '5641', 'e', 'q', 'h', 'p', '6243', '9063', '4859', 'g', '7197', 'r', 'y', '9787', 't', 'l', 't', 'g', 'i', '2363', 'h', 'h', '3245', '179', 'q', 'c', 'm', 'd']

SOLUTION:
a, c, d, e, g, h, i, l, m, o, p, q, r, s, t, u, y