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: ['m', '3809', 'l', 'k', '1929', '7963', 'n', 'u', '2125', 'g', 'o', '8325', 'o', 'h', 'y', '3025', 'e', 'e', 'c', 'x', '8445', '4979', 'z', 'f', '4201', '4765', 'g']

SOLUTION: c, e, f, g, h, k, l, m, n, o, u, x, y, z

PROBLEM: ['c', '8785', 'u', 'i', 'i', '6513', '6093', 'w', 'i', 'x', '9377', 'p', '1545', '7997', 'a', 'c', '125', 'u', '9149', '9103', 'u', 'o', 'h', '2275', '8503', '3251', 'c', '9925', 'w', '6873', 'c', 'h', 'e', '2369', 'c', 'z', '1337', '9541', '675', 's']

SOLUTION: a, c, e, h, i, o, p, s, u, w, x, z

PROBLEM: ['2181', '5759', 't', 'l']

SOLUTION:
l, t