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: ['f', '9203', 'w', 'f', '3751', '8095', '1319', 'f', '3017', 'r', 'y', '8221', '2715', '9959']

Answer: f, r, w, y


Question: ['f', '3409', 'i', '4147', '1745', '6007', 'l', 'd', 'i']

Answer: d, f, i, l


Question: ['a', 'o', 'g', 't', '8667', '1207', 'v', '4651', '3205', '3349', 'a', '2245', '3693', 'g', '6531', '7567', '999', 'i', '6895', '2685', '6835', 'w', '2129', 't', '6817', 't', '907', 'u', '1849', '7683', '2663']

Answer:
a, g, i, o, t, u, v, w