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: ['6585', 'i', 'p', '5623', '3557', '8011', 'c', '6389', 'h', 'h', 'd', '1823', '5567', 'v', 'p', 'x', 'c', '2161', '3649', 'o', '6227', 'f', '9975', 'd', 'm', '2587', 'o', 't', 'k', '7637', 'm', 'l']

SOLUTION: c, d, f, h, i, k, l, m, o, p, t, v, x

PROBLEM: ['r', 'j', '437', 'b', '5223', 'n', 'v', '437', 'd', '8285', 'k', 'j', 'r', 'p', 'n', 'e', 'n', 'j', 'o', '2651', 'j', '6365', 'q', 'q', '2159', 'g', '3641', '7727', 'c', '1197', 's', 't', 'n']

SOLUTION: b, c, d, e, g, j, k, n, o, p, q, r, s, t, v

PROBLEM: ['205', '5529', '5699', 'e', '5049', 'w', 'w', '2085', 'p', 'n', '4921', 'y', '8481', '5551', 'l', 'l', 'i', '4241', 'v', '3465', 't', 'e', 'k', 'e', '3417', '3915', '7013', 'q', 'c', 'i', 'n', 'r', 'i', '9093', '5699', 'd', '1467', 'u']

SOLUTION:
c, d, e, i, k, l, n, p, q, r, t, u, v, w, y