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.
--------
Question: ['9385', '4021', 'y', '9629', 'u', '7623', 'd', '5155', 'x', '2605', '8893', 'l', 'p', 'a', 'm', '6699', 'i', '4503', '6623', 'm', 'l', '6115', 'p', 'w', '9691', '811', '4769', '2659', 'x', 'c', '6513', '5499', 's', 'q', 'f', 'v', 'z', 'w', 'z', '1361']

Answer: a, c, d, f, i, l, m, p, q, s, u, v, w, x, y, z


Question: ['2453', 'r', 'd', '8499', 't', 's', 'h', 'a', 'm', '9271', 'g', '2599', '6209', 'o', 'i', '4069', 't', '6793', '7679', '6643', '7359', 'm', 'f', 'w', '775', '3347', '6161', '9745', 'i']

Answer: a, d, f, g, h, i, m, o, r, s, t, w


Question: ['165', 'j', 'v', 'i', 'j', '4983', 'o', '8131', 'y', 'r', '6795', '7517', '5253', '5663', '1837', 'r', 'k', 'y', '1169', '1015', '9785', 'b', '4551', '8299', '3781', 'z']

Answer:
b, i, j, k, o, r, v, y, z


