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: ['l', '1213', 'm', 'k', '7825', '3501', '2397', '2313', 'v', '4119', 'h', 't', '6137', 'l', '9851', 'q', '9661', 'b', 'z', '1437', '1759', 'l', '611', '5085', '4443', 'n', 'u', 'b', '2511', '6023', '7157', 'n', '9921', 'o', 'a', 'o', 'w', 't', 'o', '1607', '6751', 'n', 'b']

A: a, b, h, k, l, m, n, o, q, t, u, v, w, z
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Q: ['k', '8551', 'n', 'k', '211', 'g', 'w', 'q', '4045', '8037']

A:
g, k, n, q, w
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