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: ['b', 't', '2199', 'e', 'i', '1883', '5137', '8495', 't', '7377', 'm', '7665', '2009', 'o', '3757', 'm', '861', 'm', 'l', '9229', 'c', 'r', 'q', 'i', 'm', '705', 'b', '4301', 'd', 'l', 'f', '5485', 'h', 'p', '4529', '7879', 'f', 'b', 'm']

Answer: b, c, d, e, f, h, i, l, m, o, p, q, r, t


Question: ['9271', '6393', '6005', 'x', '2301', '3999', 'p', 'z', 'j', '1033', '7555', 'r', 'r', 'y', '8917', '5939', '4031', 'e', '8095', 'g', '6095', 'a', '4133', '6471', '2129', '8021', '1093', 't', '8805', '545', 'k', '3249', 'l', '1561', '9909', 's', '1963', 'o']

Answer: a, e, g, j, k, l, o, p, r, s, t, x, y, z


Question: ['f', '9497', '9063', '671', '5421']

Answer:
f