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: ['6737', 'g', '9985', '5257', 'k', 't', '7863', 'y', '8319', 'l', 'o', '6505', '6531', 'z', '3055', '2943', '3625', 'h', '4867']

Answer: g, h, k, l, o, t, y, z


Question: ['f', 'j', '9195', '3155', '2855', '5333', '5263', '9279', '687', 'e', '3055', '7233', '13', 'j', 'p', 'i', '8327', 'm', 'h', '3977', 'h', '7997', 'a', 'h', '4661', 'x', '8237', 'a', '5009', 'o', 'p', 'z', '2293', 'q', 'p', '5469', 'k', 'q', 'b', 'n', '1967', '4991']

Answer: a, b, e, f, h, i, j, k, m, n, o, p, q, x, z


Question: ['a', 'd', '1627', 'j', 'i', '587', '6411', '705', 't', '463', '1889', '2267', 'z', 'd', '181', '4219', 'f', '785', '1619', 'n', '6583', '3707', '5561', '3049', '8801', 'd', 'i', '7821', '4659', 't', 'p', '8587', '6181', '7537', 'o', '8703', '3269', '8163', 'x', 't', 'x', '2349']

Answer:
a, d, f, i, j, n, o, p, t, x, z