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: ['a', 'i', '7725', '2483', 'e', 'j', '5337', 'b', '6835', '8231', 'm', 'v', 'a', '1475', 'n', '5823', 's', 'm', '7313', '2841', '2585', '4673', 'u', '2083', 'z', 'd', 'p', '2117', 'i', '587', 'i', 'a', '2527', '7967', '6567', 'n', '6145', 'r', 'f']

SOLUTION: a, b, d, e, f, i, j, m, n, p, r, s, u, v, z

PROBLEM: ['2505', '4199', 'e', '5433', '8795', 'q', 'i', '9357', 'o', '257', '8235', 'b', '1339', 'w', '1463', 'm', '277', '3211', '3863', 'r', 'm', 'i', '5793', '7451', '4787', '4739', 'k', 't', 'o', '7453', '9385', 'v', 'l', 'y', 'f', 'r', 'p', 'w']

SOLUTION: b, e, f, i, k, l, m, o, p, q, r, t, v, w, y

PROBLEM: ['n', 'h', 'a', 'z', 'x', '9199', 'u', '4423', '1675', 'j', '403', 'h', 'u', '1167', '1147', 'k', '8217', 'm', '2017', 'k', '4103', '5359', 'p', '5043', 't', 'z', '9053', 's', 'd', 'y', '6307', '7165', '2129', '8149', 'f', '5331', '225', 't', '6939', 'b', '4057', '2073', '7923']

SOLUTION:
a, b, d, f, h, j, k, m, n, p, s, t, u, x, y, z