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: ['1233', '405', '8901', '7147', '8841', 's', 'v', '3131', 'p', 'd', 'y', '5873', '439']

Answer: d, p, s, v, y


Question: ['7965', '6465', 'c', '7963', 'j', '6839', '9989', '1019', 'x', '1303', '2633', 'y', '6865', 'a', 'k', '635', '3719', '7229', 'k', 't', 'r', '5741', '9569', '4931', '1125', 'f', '5429', 'c', '2065', '6315', 'e', '6877', '2005', 'x', '7831', '7297', 'm', '3571', 'b', '8617', '2981', 'i', '5105', 'g', 'u']

Answer: a, b, c, e, f, g, i, j, k, m, r, t, u, x, y


Question: ['y', '4249', '9653', 'n', '1037', '6569', 'k', 'u', '4589', 'm', '4273', 'r', 'l', '3349', '4051', 's', '9069']

Answer:
k, l, m, n, r, s, u, y