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: ['8311', 'w', 'f', '3431', '9863', '5817', '3969', '2705', 'x', 'm', 'k', 'z', 'z', '235', 'x', '417', 's', 'i', 'y', '8833', '8675', 's', 'm', '2149', '765', 'u', '1021', '7823', 'x', '7275', '3157', 'k']

Answer: f, i, k, m, s, u, w, x, y, z


Question: ['z', '3219', '6399', '2357', '7597', '357', 'k', 'k', 'u', 'd', '6115', 'w', '2921', '8809']

Answer: d, k, u, w, z


Question: ['8085', 'j', '2803', '3833', 'u', 'i', '5839', '49', '8299', '55', '1583', 'r', 'z', '7909', 'u', 'e', '6393']

Answer:
e, i, j, r, u, z