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: ['s', 'w', 'c', '4137', 't', '2437', '349', 'h', '4539', 't', 'b', 'y', 'q', 't', '9087', 'c', '9489', '6285', '6247', '8353', 'n', 't', '8661', 'p', 'z', 'p', '773', 'w', 'q', '8081', 'r', 'u', 'z', 'k', 'a', 'b', '7513', '5549', '5325', '1101', 's', '6507', '3317']

Answer: a, b, c, h, k, n, p, q, r, s, t, u, w, y, z


Question: ['n', 'w', '6735', '3427', '6115', 'q', '7851', '3645', 'g', '6825', '6515', '4885', 'z']

Answer: g, n, q, w, z


Question: ['y', 'l', '461', 'w', 'l', 'i', '5479', 'q', 'i', 'x', '4925', 'd', '3517', 'e', '5497', '9235', '3881', '3567', 'e', 'g', 'h', 'a', 'r', '6969', '1779', 'n', 'm', 'n', 'a', '2453', '501', '8545', 'l']

Answer:
a, d, e, g, h, i, l, m, n, q, r, w, x, y