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: ['v', '6635', '5395', '3263', '4391', 'h', '1521', 'f', '9861', '6125', '1673', '3679', '8681', '4967', 'f', 'a', 'c', 'k', 'n', '4155', 'e', 'm', 'i', '1699', 'r', 'f', 'u', 'r', '3451', 'v', '7239', 'o', '4359', 'l', 'a', '2925']

Answer: a, c, e, f, h, i, k, l, m, n, o, r, u, v


Question: ['7065', 'q', 't', '3177', '9035', 'i', 'l', 'd', '8961', '1183', '6507', 'u', 'c', 't', '2467', '7659', 'e', '8963', 'j', 'g', 'p', '6779', '7115']

Answer: c, d, e, g, i, j, l, p, q, t, u


Question: ['2661', '5799', 'l', 'z', '4907', '4653', 'x', '9871', '1335', 'b', 'b', 's', '1885', 'j', '1423', '3725', 'h', 't', '1229', '3199', 'k', '5179', 'c', 'v', 'w', '4283']

Answer:
b, c, h, j, k, l, s, t, v, w, x, z