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: ['8235', 't', '1695', '9899', '3633', 't', '1823', 'r', 'x']

Answer: r, t, x


Question: ['1063', 'f', 'm', 'i', 'x', 'i', 'd']

Answer: d, f, i, m, x


Question: ['8309', '1305', '319', '5609', 'r', '8983', '439', '3753', '7361', 'b', 's', 'n', '9959', 'r', '6373', 'r', '9743', '5915', 'a', '531', '551', 'j', '5339', 'f', '4237', '8267', '9215', '5407', '1323', 'r', '7111', '3975', '4861', '1527', 'r', 'i']

Answer:
a, b, f, i, j, n, r, s