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: ['459', '1729', 'b', 'c', '9619', '4461', '4347', '6733', 'i', '3631', 's', 'j', 'i', 'r', '5293', 'q', '7397', '4309', 'c', 'n', 'k', '197', 'q', '8139']

Answer: b, c, i, j, k, n, q, r, s


Question: ['z', '8407', 'y', 'h', '1377', '3511', '1449', 'z', '3991', 'n', 'x', 't', 'h', '6389', '8049', '6091', '7787', 'p', 'l', '5815', 'k', 'e', 's', 'a', '9491', 'w', '1909', '4801', '4725', 'i']

Answer: a, e, h, i, k, l, n, p, s, t, w, x, y, z


Question: ['s', '2959', '4359', '5093', '5227', 'q', '3433']

Answer:
q, s