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: ['6627', '8037', 'q', 'e', 'j', 'p', '9613', '9317', 'm', 'm', '5345', 'f', '8105', '5665', '4175', '4793', '3707', 'i', 'b', '6745', '747', '8329', '1481', 'b', '8949', 'n', '4803', '1359', '3533', 'f', '543', '3003', '6943']

Answer: b, e, f, i, j, m, n, p, q


Question: ['2381', 'y', '6631', '5839', 'r', 'm', 'z', 'b', '4663', '595', '7771', '5305', '5087', '3317', '3125', '9551', '4343', '5121', 'm', 'i', '131', '8401', '5379', '1775', 'u', '1125', '9793', '4123', 'h', '1613']

Answer: b, h, i, m, r, u, y, z


Question: ['c', '591', 'c', '2749', 'o', 'o', 'o', 'k', 'a', '6899', 'k', 'z', 'x', 's', '2497', '9101', 'i', 'k', '7921', '5011', 'l', '7405', 'a', '587', '3583', 'v', '5735', '6741', '8907', '9861', '4325', '847', 'u', '2553', 'n', '7615', '2293', 'd', '659', '5207']

Answer:
a, c, d, i, k, l, n, o, s, u, v, x, z