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: ['2741', '2541', '8943', 'l', '4047', '2211', 'p', 'e', 't', '7645', '9771', 'f', '5063', '2303', '6097', '5089', 'd', 'e', '1409', '3125', '2171', 'g', '1247', '4045', 'v', 'h', 'u', '2587', '5207', '5553', 'g', 'd', '6891', 'e', '2471', '2435']

Answer: d, e, f, g, h, l, p, t, u, v


Question: ['u', 'w', '401', 't', 'g', 'h', 'g', '8073', '9597', '1347', '7835', '5007', '977', 'p', '7679', 'b', '4883', '4931', '999', 'r', '1181', 'x', '2063', 'l', 'w', 'i', 'l', 'x', 'i', '9057', '5007', 'w', '743', '1635', 'y', 'f', '9227', 'z', '5227', 'd', '7129', 'k', '7657']

Answer: b, d, f, g, h, i, k, l, p, r, t, u, w, x, y, z


Question: ['y', 'u', '9225', 'r', 'd', 'b', '3587', 'h', '3195', 'z', '1051', '5397', '263', 'f', 'n', '4801', '213', '3345', '133', '9367', '9873', '2045', 'h', '7437', '349', 'm', 'l', '1341', 'g', '8125', 'v', 'z', '1205', 'k', '4049', 'w', '9275', 'm', 'i', '2379', 'g', 'h', 'q']

Answer:
b, d, f, g, h, i, k, l, m, n, q, r, u, v, w, y, z