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: ['2995', '8179', '8131', '5655', 'j', 'q', 'l', '3193', '1823', 'y', 'n', '7645', 's', '5665', 'r']

Answer: j, l, n, q, r, s, y


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: ['2133', '1689', '715', '4371', '669', '1247', '8339', 'o', '3651', 'w', 'h', 'x', '4645', 'd', 'j', 'c', 'q', '5861']

Answer:
c, d, h, j, o, q, w, x