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: ['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: ['k', 'c', 'i']

SOLUTION: c, i, k

PROBLEM: ['8267', 'u', '4415', 'o', '8757', '361', 'q', '7165', 'w', '8703', '1623', 'e', 'o', 'v', '7577', '1501', 'x', 'c', '7685', 'q', '2749', 's', '85', '5525', '6427', 's', 'g', 'k', 'z', 'l', 'p', '8477', 'h', '7389', '7181', '7', 'g', '3085', 'g', '9833', 'l']

SOLUTION:
c, e, g, h, k, l, o, p, q, s, u, v, w, x, z