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.
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Question: ['r', 'y', 'c', '3211', '9245', '8459', '8521', '5781', 'w', 's', 'd', '5299', 'a', 'y', 'g', 'm', '6435', '8605', 'e', 'h', '6871', 's', '387', 'l', '5829', 'e', 'd', '9545', '2945', 'k', 'v', 't', '8449', '2199', 'm', '2599', '1489', '6623', 'x', 'l']

Answer: a, c, d, e, g, h, k, l, m, r, s, t, v, w, x, y


Question: ['4787', 'c', '1727', '9863', '8147', '3931', 'b', '1133', '3023', '7427', '7837', 'n', '7921', 'o', 'c', '3973', '1949', 'x', 'g', 'b', 'd', '8559', '8661', '4465', 'z', '369', 'q', 'e', 'y', '8629', '7665', 'i', 'r', 'n', 'z', '9115', '1393', '4899']

Answer: b, c, d, e, g, i, n, o, q, r, x, y, z


Question: ['g', 'i', '8417', '2447', '159', '2169', '8313', 'e', '7559', '8311', 'c', 'm', '5127', 'h', '789', '9381', 't', '9127', '3723', 'e', '5435', 'f', 'z', 'v', '9101', '1991', 'x', '5673', 'w', 'i']

Answer:
c, e, f, g, h, i, m, t, v, w, x, z