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', '6003', 'k', '1987', '1877', 'a', '2615', 'n', 's', 'f', 'b', 'm', '1149', '8293', '5803', 'e', '2697', '5917', 'p', '6035', '2385', 'i', 'u', 'm', '9565', '4523', 'b', 'v', '2577', '9725', '6093', '6203', '4197', '8477', 'o', 'd', '3637', '9827', '5523', '7189', 'j', '8893', 'h', 'q']

Answer: a, b, d, e, f, h, i, j, k, m, n, o, p, q, s, u, v


Question: ['6955', '721', '2763', '8121', '9109', '6341', 'p', 't', 'x', '6963', '1137', 'z', 'u', '1949', '7029', 't', '9539', 'a', 'u', '1873']

Answer: a, p, t, u, x, z


Question: ['1039', 'f', 'v', 'j', 'j', '6317', 't', 'c']

Answer:
c, f, j, t, v