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: ['z', 'm', 'n', 'u', '9159', '7931', '5401', '1383', '8195', 't', 'x', 'q', 'r', '2535', 's', 'j', 'c', '8123', '2429', '5581', 'k', 'c', 't', 'i', 'm', 'o', 't', 'q', '4819', 't', '1649', 'r', 'y', 'z', '8813', '7451', '199', 'o', 'x', 's', 's', '6747']

Answer: c, i, j, k, m, n, o, q, r, s, t, u, x, y, z


Question: ['i', '9215', 'n', 'p', '4815', '8757', 'm', '1755', 'c', 'z']

Answer: c, i, m, n, p, z


Question: ['f', 'z', '7625', 'c', '3885', 'y', '7783']

Answer:
c, f, y, z