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: ['7073', 'd', 'e']

SOLUTION: d, e

PROBLEM: ['3925', 'i', '3797', 'q', '2977', 'v', 'b', 'p', '3551', 'w', '7433', 'y', '1595', '8265', 'k', '5687', 'w', '7413']

SOLUTION:
b, i, k, p, q, v, w, y

