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: ['7799', '8163', '3389', 'x', 'k', 'm', '6085', 'f', '1131']

SOLUTION: f, k, m, x

PROBLEM: ['q', '8149', '4087', '5183', 't', 'j', 'e', 'g', 'r', '2125', 'y', 'l', 'g', '3673', 's', 'r', 'e', 'v', '4259', 'v', '3477', '9353', '3639', 'v', 'n', 'e', 'z', '5071', 'x', '6287', 'e', 'e']

SOLUTION: e, g, j, l, n, q, r, s, t, v, x, y, z

PROBLEM: ['2253', 'q', '3147', '9159']

SOLUTION:
q