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.

Q: ['e', 'z', '5199', 'x']

A: e, x, z
****
Q: ['7777', '6223', 'k', 'k', 'd', '9743', '189', '7705', 'c', '6115', '4275']

A: c, d, k
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Q: ['1051', 'b', 's', 'x', 'o', 'x', '2931', '2463', '8635', 'a', 'm', 'w', 'i', 'c', '9377', 'h']

A:
a, b, c, h, i, m, o, s, w, x
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