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: ['u', '4021', 'u', 'd', 'j', 'p', 'i', 'z', '3223', 'f', 's', 'l', 'p', 'd', '5031', '1059', '7875', '2097', 'q', 'i', '8813', '2017', 'h', 'l', 'y', '57', '1561', 'f', 'j', 'z', '1901', 'u', 'j', 'x', '6561', '9239', '3333', '8793', '4915', '5821', 'h', 'f', '765', 'x']

Answer: d, f, h, i, j, l, p, q, s, u, x, y, z


Question: ['n', '7489', 'n', 'n', '9787', '7829', 'n', '3481', 'v', 'l', '8927', 'c', 'm', 'd']

Answer: c, d, l, m, n, v


Question: ['q', '8571', 'n', '9555', '1871', '1077', '8051', 'b', '5391', '9417', 'z', '4405', '5959', 'p', '9121', '7899', 'j', '1235', '1987', 'c', '4841', 'q']

Answer:
b, c, j, n, p, q, z