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: ['2593', '1835', '5089', 'v', '9723', 'f', '9279', '4257', '2175', '655', 'q', 's', 'v', 'j', 'm', '4471', '6419', '1685', '2793', 'x', '509', 's', '4833', '2125', 'b', '6379', '1075']

SOLUTION: b, f, j, m, q, s, v, x

PROBLEM: ['4417', 'x', '4641', '885', '8485', 'd', '7057', '8519', 'm', 'i', 'l', '4627', '3069', 'v', '5011', 'u', '6673', 'h', '4541', 'j', '2337', '8175', '4797', 'f', '9109', 'q', 'q']

SOLUTION: d, f, h, i, j, l, m, q, u, v, x

PROBLEM: ['t', '7545', '611', '529', '655', '2439', '3921', 'y', 'h', 'i', 'o', '3735', '9939', 'l', 'm', 'n', 'y', 't', 'r', '3503', 'l', '8759', '3809', '1229', '5479']

SOLUTION:
h, i, l, m, n, o, r, t, y