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
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Q: ['a', 'w', 'm', 'g', 'c', '5475', '7391', 't', '1049', 'p', 'd', '1397', 'k', 'x', 'j', '2525', 'f', '741']

A: a, c, d, f, g, j, k, m, p, t, w, x
****
Q: ['k', 't', '5195']

A:
k, t
****