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: ['k', 'r', 'f', '4369', 'z', 'z', 'l', '143', 'r', '707', '9167', 'g', '1749', 'i']

Answer: f, g, i, k, l, r, z


Question: ['b', 'd', '8153', 'u', '3695', '5317']

Answer: b, d, u


Question: ['m', '5007', 'v', '9551', '8423', '7371', '3191', '4421', '6213', 'b', 'c', 'k', '6437', 'a', 't', 'e', '8613', 'a', '5355', '4983', '8079', 'v', 'h', '867', 'v', '7661', 'w', '6625', '1277', 'c']

Answer:
a, b, c, e, h, k, m, t, v, w