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: ['5431', 'o', 'u', 'l', 'f', 'd', 'r', '1479', '9357', 's', 'v', '6399', 'b', '7937', 't', '8497', 'r', '131', 'h', 'c', 'v', '8879', 'k', 'r', '4687', 'l', '1065', 'r', 'w', 'l', '3305', '461', 'q', 'h', 'b', 'e', 'e', 'w', '5999']

Answer: b, c, d, e, f, h, k, l, o, q, r, s, t, u, v, w


Question: ['3797', '6117', 'x']

Answer: x


Question: ['w', '2523', 'y', '6369', 'f', '1775', '1039', '1301', '6029', '2061', '4295']

Answer:
f, w, y