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: ['d', '2359', '6571', 'c', 'n', 'u', '9513', '9321', '1689', 'b', '969', '1823', 'e', 'b', '9147', 's', '1811', 'k', '5443', '8699', '5483', 'v', 'w', 'n', '1215']

Answer: b, c, d, e, k, n, s, u, v, w


Question: ['9925', 'f', '6149', 's', 'd', 's', '75', '8577', '2319', 'b', '3769', '5211', 'q', 'm', '8127', 'f', '3801']

Answer: b, d, f, m, q, s


Question: ['6359', 's', '1811', 'p', 'z', '7227', 'q', 'z', 'i', 'l', 'v', '641', '3443', 'm', '2553', '3483', '3441', 'j', 'k', '9937', 'p', 'a', '7729', 'o', '5957', 'f', '5309', '5073', '1525']

Answer:
a, f, i, j, k, l, m, o, p, q, s, v, z