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: ['6463', '871', '5781', '283', '9653', 'f', '9661', '3365', '2889', '5499']

A: f
****
Q: ['8315', 'b', '4333', 'f', '6507', '6211', '3475', 'c', 'e', '8039', '661']

A: b, c, e, f
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Q: ['d', '1989', '6365', 'y', 'm', '1245', '7539', 'm', '3787', '6987', 'e', 'e', 'y', '9577', 'b', '5', '8179', 'x', '2853', '6337', 'w', 'f', 'b', 'q', '563', '6077', '1133', 'x', '6045']

A:
b, d, e, f, m, q, w, x, y
****