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: ['d', '4377', '9271', '8053', '9519']

Answer: d


Question: ['5785', 'c', 'f', '7087', 'd', '9225', 'm', 'g', '4639', '7165', '3445', '3813', 'p', 'i', '719', 's', 'g', '6423', '9563', 'w', 'm', '8659', '8809', '4105', '3923', '465', '5637', '5547', 'h', 'v', '9453', '4009']

Answer: c, d, f, g, h, i, m, p, s, v, w


Question: ['l', 'e', '2707', 't', '5473', 'k', 'z', 'y', '2841', '6667']

Answer:
e, k, l, t, y, z