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: ['9925', 'f', '6149', 's', 'd', 's', '75', '8577', '2319', 'b', '3769', '5211', 'q', 'm', '8127', 'f', '3801']

Answer: b, d, f, m, q, s


Question: ['7301', '7999', 'x', 'r', '6881', 'e', '609', 's', '7495', 'a', 's', '1961', 'q', 'x', '373', '6289', '4847', '5969', 't', '5487', '7639', '9039', '2395', 'b', 'd', '1447', 's', '8137', 's', '443', 'f', 'z', '4823', 'k', 'i', 'o', '4739', 'w', 'f', '8853', 'a']

Answer: a, b, d, e, f, i, k, o, q, r, s, t, w, x, z


Question: ['d', '5459', 'q', 'f', '4615', '7877', '8601', '1751', 'm', 't', 'w', 'h', '7523', '9605', 'c', '3809', 'd', '8197', '8697']

Answer:
c, d, f, h, m, q, t, w