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: ['9013', 'e', 'm', 'p', 'k', '161', 'k']

Answer: e, k, m, p


Question: ['4031', 't', 'o', 'c', 'x', '3007', '8329', '6345', '1267', '1017', 'o', 'x', 'l', '4129', 'd', '1987', '487', 'o', 'g', 'j', 'v', 'x', '3983', 'f', 'g', '5759', 'k', 'i', 'o', 'b', 'n', '683', 'j', 'o', 't', '4361', 'u']

Answer: b, c, d, f, g, i, j, k, l, n, o, t, u, v, x


Question: ['s', 'z', '5921', '6611', 'o', '1613', 'p', '4725', 'f', 'h', 'g', 'k', 'w', '2853', '2555', 'h', 't', '2733', '9733', '8115']

Answer:
f, g, h, k, o, p, s, t, w, z