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: ['x', '4283', 'n', 'b', 'g', 'p', '8305', '7781', '5907', 's', '1305', 'w', '8623', 'o', 'c', 'u', '1839', '2869', '7537', 'y', '2395', '5309', 'e', '4059', 'l', '6647', 'p', '9717', 'y', 'y', '3769', '2527', '2981', '5255', '4063', 'j', '4843', 'j', '9355', 'z']

Answer: b, c, e, g, j, l, n, o, p, s, u, w, x, y, z


Question: ['6597', '7889', 'x', 'v', 'm', 'j', 'j', 'w', 'v', '177', 'x', '8353', '5897']

Answer: j, m, v, w, x


Question: ['t', '9375', 't', 'r', 'b', '1309', 'w', '3251', '9153', '6249', '1561', 'u', '6127', 's', '6863', '3667', '5957', '953', '1697', 'd', 'x', 'o', '275', '111', '7421', '4573', 'k', '9695', 'c', 'v', 'c', 'k', '7549', '6651', '7851', 'h', '5541', '541', 'a', '6355', 'k', '6055', '5351']

Answer:
a, b, c, d, h, k, o, r, s, t, u, v, w, x