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: ['4945', 'i', 'h', 's', '8925', 'i', '3995', 'f', '813', '1823', '3475', 'q', '2463', '9487', 'c', 'c', 'n', 'y', 's', '6269', 'a', 'u', 'd', 'd', '9291', '3187', '545', '7929', 'd', '1007', '7579', '8421', '4033', 'v', 'c', 'e', 'n', 'j']

SOLUTION: a, c, d, e, f, h, i, j, n, q, s, u, v, y

PROBLEM: ['5957', 'd', 'i', 'b', 'e', '5565', 'c', 'i', '2919']

SOLUTION: b, c, d, e, i

PROBLEM: ['y', '4129', '801', '4145', '2635', 'o', '9387', 'q', 'v', '2383', '4679', 's', 'i', 'u', '3343', '4207', 'd', 'p', 'd', '4481', '8557']

SOLUTION:
d, i, o, p, q, s, u, v, y