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: ['7065', 'q', 't', '3177', '9035', 'i', 'l', 'd', '8961', '1183', '6507', 'u', 'c', 't', '2467', '7659', 'e', '8963', 'j', 'g', 'p', '6779', '7115']

Answer: c, d, e, g, i, j, l, p, q, t, u


Question: ['699', 'd', '6027', 'j', 'e', 'c', 't', '9983', '5471', '2649', 't', '2631', 'r', 'h', '293', 'j', '8699', 'p', 'k', '5433']

Answer: c, d, e, h, j, k, p, r, t


Question: ['9717', 'p', 'e', 'e', 'v', 'k', '2149', 'p', '3373', 'h', 'x', 'w', '9899', '8635', 'c', '6223', 'f', '4065', 't', '843', '999', 'l', '7551', 'w']

Answer:
c, e, f, h, k, l, p, t, v, w, x