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: ['j', '1733', 'p', '6741', '7933', '8943', '733', 'x', '1107', 'z', '1719', '7653', 'y', 'z', '6563', 'p', '4615', 'j', '4489', 'h', 'w', 'y', 'p', 'c', '7949', 'k', 'm', 'r', '9427', '7243', '9777', 'j', '323', '4095', 't']

Answer: c, h, j, k, m, p, r, t, w, x, y, z


Question: ['y', 'i', '257', '3695', 's', '6717', '4817', '4117']

Answer: i, s, y


Question: ['w', 'n', 't', 'c', 'n', '2513', '7637', '3537', '7187', '3687', 'z', '7671', '8253', '491', 'a', 'e', 'f', '9447', '9465', '8171', 'i', '7687', '9853', '615', '6335', 'n', 'b']

Answer:
a, b, c, e, f, i, n, t, w, z