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: ['j', 'f', '9567', 'f', '7383', 'k', '599', '1091', '1501', 'y', 'o', 'c']

SOLUTION: c, f, j, k, o, y

PROBLEM: ['9013', 'e', 'm', 'p', 'k', '161', 'k']

SOLUTION: e, k, m, p

PROBLEM: ['i', '5621', '5001', '655', 'g', '3933', '7761', 'r', 'o', 'v', '7449', 'r', '499', '8773', '8379', '9059', 'd', 'l', '4367', '3115', '8303', '3603', 'j', 'l', 'p']

SOLUTION:
d, g, i, j, l, o, p, r, v