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.
--------
Question: ['9425', 'l', 'c', 'n', '5925', '2543', '3935', 'c', '7533', 'j', 'q', '3775', '5897', '9435', '69', 'e']

Answer: c, e, j, l, n, q


Question: ['r', '9489', 'e', 'n', '6323', 'd', '3163', '265', '8587', '7891']

Answer: d, e, n, r


Question: ['i', '789', 'v', 'u', '6631', 'l', '7193', '2171', '8401', 'e', '8951', '4577', 'p', '8591', 'v', 'c', '8187', 'o', 'l', '4405', '295', 'm', '9669', 'e', 'i', 'u', 'y', '9207', '1299', '4909', '9941', '1007', 'm', 'p', 'v', '7375', '5837', '7601', 'y', '551', 'g', 's', 'q', '4859', '4831']

Answer:
c, e, g, i, l, m, o, p, q, s, u, v, y