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: ['5489', 'f', '6833', 's', 'c', '6575', 'w', '2957', '8465', 'v', 'h', '2119', '7731', 'e', '5367', 'e', '3357', 'p', '7565', 'n', 'x', 'n', 'f', '1075', '5941', '6505', 'j', 'p', '2853', 'l', 'q', '4727', 's']

SOLUTION: c, e, f, h, j, l, n, p, q, s, v, w, x

PROBLEM: ['5737', 'b', 'e', 't', '7419', 'n', 'y', '5225', '6485', 'b', '1343']

SOLUTION: b, e, n, t, y

PROBLEM: ['s', 'h', 'j', 'w', 'x', 'f', 'm', '9205', 'q', '6877', '6441', 'd', 'g', 'e', 'p', '7699', '5625', '3927', '5067', '5275', 'b', '955', '8015', 'g', '7989', 'r', '9771', 'p', '6997', '4527', 'e', '8063', '9279', '3049', 'p', '1051']

SOLUTION:
b, d, e, f, g, h, j, m, p, q, r, s, w, x