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: ['8235', 't', '1695', '9899', '3633', 't', '1823', 'r', 'x']

Answer: r, t, x


Question: ['h', 'b', '9601', 'h', 'h', 'h', '8099', '8265', 'i', 'd', '8791', 'p', '8059', '4309', '501', '2581', '9837', '157', '4785', '5925', 'q', '8491', '4779', 'r', 'l', 'k', '3679', 'v', 'g', 'g', '9731', '1909', '9783', 'f', '4293', '5009', 'o', '3057', '3157', 'c', '5587', 'b', 'f', 'd', 'k']

Answer: b, c, d, f, g, h, i, k, l, o, p, q, r, v


Question: ['a', 'i', '7725', '2483', 'e', 'j', '5337', 'b', '6835', '8231', 'm', 'v', 'a', '1475', 'n', '5823', 's', 'm', '7313', '2841', '2585', '4673', 'u', '2083', 'z', 'd', 'p', '2117', 'i', '587', 'i', 'a', '2527', '7967', '6567', 'n', '6145', 'r', 'f']

Answer:
a, b, d, e, f, i, j, m, n, p, r, s, u, v, z